{"asset": "plumbing-fitting-thread-standards", "asset_type": "lookup", "body": "Dimensional specifications for NPT and BSP pipe thread sizes used in plumbing, hydraulic, and gas fittings worldwide. For each nominal pipe size within each standard, gives threads per inch, pitch, major diameter, and minor diameter \u2014 the numbers needed to identify an unknown thread or confirm whether two fittings will mate. Combines American (ASME B1.20.1) and British/ISO (ISO 228, ISO 7) standards in one table so the critical differences are visible side by side.\n", "description": "Dimensional specifications for NPT and BSP pipe thread sizes used in plumbing, hydraulic, and gas fittings worldwide. For each nominal pipe size within each standard, gives threads per inch, pitch, major diameter, and minor diameter \u2014 the numbers needed to identify an unknown thread or confirm whether two fittings will mate. Combines American (ASME B1.20.1) and British/ISO (ISO 228, ISO 7) standards in one table so the critical differences are visible side by side.", "file": "index.md", "generated": true, "harvested": "2026-08-12", "key_field": "nominal_size", "licence": "factual compilation of thread dimensions from public reference sources; facts cited with attributed quotes, no standard document reproduced", "sources": ["https://www.machiningdoctor.com/charts/bsp/", "https://en.wikipedia.org/wiki/National_pipe_thread", "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "https://en.wikipedia.org/wiki/British_Standard_Pipe", "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "title": "Plumbing fitting and pipe thread standards", "type": "dataset", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 47.80\n\n**Minor diameter (mm):** 44.85\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:\n\nSource: \n", "file": "1-1-2-2-2.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-1-2-2-2", "major_diameter_mm": "47.80", "minor_diameter_mm": "44.85", "nominal_size": "1 1/2", "source_quote": " BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "1 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1-1/2\n\n**Threads per inch (TPI):** 11 1/2\n\n**Thread pitch (mm):** 2.2087\n\n**Major (outside) diameter (mm):** 48.2600\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1.900 | 48.2600 |\n\nSource: \n", "file": "1-1-2-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-1-2-2", "major_diameter_mm": "48.2600", "nominal_size": "1-1/2", "source_quote": "1.900 | 48.2600 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.2087", "thread_standard": "NPT", "threads_per_inch": "11 1/2", "title": "1-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 47.803\n\n**Minor diameter (mm):** 44.846\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1 1/2 | 1 1/2\" | 11 | 2.309 | 47.803 | 46.324 | 44.846\n\nSource: \n", "file": "1-1-2-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-2-3", "major_diameter_mm": "47.803", "minor_diameter_mm": "44.846", "nominal_size": "1 1/2", "source_quote": "BSPP G 1 1/2 | 1 1/2\" | 11 | 2.309 | 47.803 | 46.324 | 44.846", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "1 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/2 Inch BSP\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 47.80\n\n> 1-1/2 Inch BSP | 47.80 mm | 45.5 mm | 11\n\nSource: \n", "file": "1-1-2-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-1-2-inch-bsp", "major_diameter_mm": "47.80", "nominal_size": "1-1/2 Inch BSP", "source_quote": "1-1/2 Inch BSP | 47.80 mm | 45.5 mm | 11", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/2 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 47.803\n\n**Minor diameter (mm):** 44.845\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1\u00bd | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 |\n\nSource: \n", "file": "1-1-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-2", "major_diameter_mm": "47.803", "minor_diameter_mm": "44.845", "nominal_size": "1-1/2", "source_quote": "1\u00bd | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_standard", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1 1/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 41.91\n\n**Minor diameter (mm):** 38.95\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:\n\nSource: \n", "file": "1-1-4-2-2.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-1-4-2-2", "major_diameter_mm": "41.91", "minor_diameter_mm": "38.95", "nominal_size": "1 1/4", "source_quote": " BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "1 1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1-1/4\n\n**Threads per inch (TPI):** 11 1/2\n\n**Thread pitch (mm):** 2.2087\n\n**Major (outside) diameter (mm):** 42.1640\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1.660 | 42.1640 |\n\nSource: \n", "file": "1-1-4-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-1-4-2", "major_diameter_mm": "42.1640", "nominal_size": "1-1/4", "source_quote": "1.660 | 42.1640 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.2087", "thread_standard": "NPT", "threads_per_inch": "11 1/2", "title": "1-1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1 1/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 41.910\n\n**Minor diameter (mm):** 38.953\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1 1/4 | 1 1/4\" | 11 | 2.309 | 41.910 | 40.431 | 38.953\n\nSource: \n", "file": "1-1-4-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-4-3", "major_diameter_mm": "41.910", "minor_diameter_mm": "38.953", "nominal_size": "1 1/4", "source_quote": "BSPP G 1 1/4 | 1 1/4\" | 11 | 2.309 | 41.910 | 40.431 | 38.953", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "1 1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/4 Inch BSP\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 41.91\n\n> 1-1/4 Inch BSP | 41.91 mm | 39.6 mm | 11\n\nSource: \n", "file": "1-1-4-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-1-4-inch-bsp", "major_diameter_mm": "41.91", "nominal_size": "1-1/4 Inch BSP", "source_quote": "1-1/4 Inch BSP | 41.91 mm | 39.6 mm | 11", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/4 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 41.910\n\n**Minor diameter (mm):** 38.952\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1\u00bc | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 |\n\nSource: \n", "file": "1-1-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-4", "major_diameter_mm": "41.910", "minor_diameter_mm": "38.952", "nominal_size": "1-1/4", "source_quote": "1\u00bc | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_standard", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1 1/8\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 37.897\n\n**Minor diameter (mm):** 34.940\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1 1/8 | 1 1/8\" | 11 | 2.309 | 37.897 | 36.418 | 34.940\n\nSource: \n", "file": "1-1-8-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-8-2", "major_diameter_mm": "37.897", "minor_diameter_mm": "34.940", "nominal_size": "1 1/8", "source_quote": "BSPP G 1 1/8 | 1 1/8\" | 11 | 2.309 | 37.897 | 36.418 | 34.940", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "1 1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/8\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 37.897\n\n**Minor diameter (mm):** 34.939\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1.4920 | 37.897\n\nSource: \n", "file": "1-1-8.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-1-8", "major_diameter_mm": "37.897", "minor_diameter_mm": "34.939", "nominal_size": "1-1/8", "source_quote": "1.4920 | 37.897", "sources": ["https://en.wikipedia.org/wiki/British_Standard_Pipe"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, minor_diameter_mm, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 33.249\n\n**Minor diameter (mm):** 30.292\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1 | 1\" | 11 | 2.309 | 33.249 | 31.770 | 30.292\n\nSource: \n", "file": "1-10.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-10", "major_diameter_mm": "33.249", "minor_diameter_mm": "30.292", "nominal_size": "1", "source_quote": "BSPP G 1 | 1\" | 11 | 2.309 | 33.249 | 31.770 | 30.292", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1/16\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 7.72\n\n**Minor diameter (mm):** 6.56\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> 111.55 | 110.07 | 0 | -999.00 | R | BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00 | BSPT Rc (Internal Tapered) Dimensions Chart Dimensions are in millimeters . To view Inch values, click the Thread Description . The below chart shows only the main dimensions. To view all the dimensions, click the thread description or use the BSPT Thread Calculator . series | Thread | Pipe OD | TPI | Pitch | Gauge Length | Tol (Turns/mm) | Major Diam | Pitch Diam | Minor Diam | Fit Allowance (Turns/mm) | Tap Drill Size | Rc | BSPT Rc 1/16 | 1/16\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 7.72 | 7.14 | 6.56 |\n\nSource: \n", "file": "1-16-2-2.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-16-2-2", "major_diameter_mm": "7.72", "minor_diameter_mm": "6.56", "nominal_size": "1/16", "source_quote": "111.55 | 110.07 | 0 | -999.00 | R | BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00 | BSPT Rc (Internal Tapered) Dimensions Chart Dimensions are in millimeters . To view Inch values, click the Thread Description . The below chart shows only the main dimensions. To view all the dimensions, click the thread description or use the BSPT Thread Calculator . series | Thread | Pipe OD | TPI | Pitch | Gauge Length | Tol (Turns/mm) | Major Diam | Pitch Diam | Minor Diam | Fit Allowance (Turns/mm) | Tap Drill Size | Rc | BSPT Rc 1/16 | 1/16\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 7.72 | 7.14 | 6.56 |", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSPT", "threads_per_inch": "28", "title": "1/16 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/16\n\n**Threads per inch (TPI):** 27\n\n**Thread pitch (mm):** 0.9407\n\n**Major (outside) diameter (mm):** 7.950\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 0.313 | 7.950 |\n\nSource: \n", "file": "1-16-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-16-2", "major_diameter_mm": "7.950", "nominal_size": "1/16", "source_quote": "0.313 | 7.950 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "0.9407", "thread_standard": "NPT", "threads_per_inch": "27", "title": "1/16 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1/16\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 7.723\n\n**Minor diameter (mm):** 6.561\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1/16 | 1/16\" | 28 | 0.907 | 7.723 | 7.142 | 6.561\n\nSource: \n", "file": "1-16-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-16-3", "major_diameter_mm": "7.723", "minor_diameter_mm": "6.561", "nominal_size": "1/16", "source_quote": "BSPP G 1/16 | 1/16\" | 28 | 0.907 | 7.723 | 7.142 | 6.561", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSPP", "threads_per_inch": "28", "title": "1/16 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/16\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 7.723\n\n**Minor diameter (mm):** 6.561\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/16 | 28 | 0.907 | 0.581 | 7.723 | 7.142 | 6.561 |\n\nSource: \n", "file": "1-16.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-16", "major_diameter_mm": "7.723", "minor_diameter_mm": "6.561", "nominal_size": "1/16", "source_quote": "1/16 | 28 | 0.907 | 0.581 | 7.723 | 7.142 | 6.561 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/16 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 20.955\n\n**Minor diameter (mm):** 18.633\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/2 | 14 | 0.0714 | 1.814 | 0.825 | 20.955 | 0.7336 | 18.633 | 0.3214 | 8.164\n\nSource: \n", "file": "1-2-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-2-2-2", "major_diameter_mm": "20.955", "minor_diameter_mm": "18.633", "nominal_size": "1/2", "source_quote": "1/2 | 14 | 0.0714 | 1.814 | 0.825 | 20.955 | 0.7336 | 18.633 | 0.3214 | 8.164", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 20.96\n\n**Minor diameter (mm):** 18.63\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> 20.96 | 19.79 | 18.63 | 0.142 | 18.5 | Rp | BSPT Rp 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 0 | 26.44 | 25.28 | 24.12 | 0.142 | 24.0 | Rp | BSPT Rp 1 | 1\" | 11 | 2.309 | 10.4 | 0 | 33.25 | 31.77 | 30.29 | 0.180 | 30.2 | Rp | BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:\n\nSource: \n", "file": "1-2-2-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-2-2-3", "major_diameter_mm": "20.96", "minor_diameter_mm": "18.63", "nominal_size": "1/2", "source_quote": "20.96 | 19.79 | 18.63 | 0.142 | 18.5 | Rp | BSPT Rp 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 0 | 26.44 | 25.28 | 24.12 | 0.142 | 24.0 | Rp | BSPT Rp 1 | 1\" | 11 | 2.309 | 10.4 | 0 | 33.25 | 31.77 | 30.29 | 0.180 | 30.2 | Rp | BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPT", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.8143\n\n**Major (outside) diameter (mm):** 21.3360\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 0.840 | 21.3360 |\n\nSource: \n", "file": "1-2-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-2-2", "major_diameter_mm": "21.3360", "nominal_size": "1/2", "source_quote": "0.840 | 21.3360 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.8143", "thread_standard": "NPT", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.81432\n\n**Major (outside) diameter (mm):** 21.34\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1/2 | 14 | 0.07143 | 1.81432 | 0.84 | 21.34\n\nSource: \n", "file": "1-2-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-2-3", "major_diameter_mm": "21.34", "nominal_size": "1/2", "source_quote": "1/2 | 14 | 0.07143 | 1.81432 | 0.84 | 21.34", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.81432", "thread_standard": "NPT", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 20.955\n\n**Minor diameter (mm):** 18.632\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1/2 | 1/2\" | 14 | 1.814 | 20.955 | 19.793 | 18.632\n\nSource: \n", "file": "1-2-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-2-4", "major_diameter_mm": "20.955", "minor_diameter_mm": "18.632", "nominal_size": "1/2", "source_quote": "BSPP G 1/2 | 1/2\" | 14 | 1.814 | 20.955 | 19.793 | 18.632", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPP", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/2 Inch BSP\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 20.99\n\n> 1/2 Inch BSP | 20.99 mm | 19.1 mm | 14\n\nSource: \n", "file": "1-2-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-2-inch-bsp", "major_diameter_mm": "20.99", "nominal_size": "1/2 Inch BSP", "source_quote": "1/2 Inch BSP | 20.99 mm | 19.1 mm | 14", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "1/2 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 20.955\n\n**Minor diameter (mm):** 18.631\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |\n\nSource: \n", "file": "1-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-2", "major_diameter_mm": "20.955", "minor_diameter_mm": "18.631", "nominal_size": "1/2", "source_quote": "1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1\u00bc\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Thread pitch (mm):** 2.20878\n\n**Major (outside) diameter (mm):** 42.16\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1\u00bc | 11\u00bd | 0.08696 | 2.20878 | 1.66 | 42.16\n\nSource: \n", "file": "1-3-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-3-2", "major_diameter_mm": "42.16", "nominal_size": "1\u00bc", "source_quote": "1\u00bc | 11\u00bd | 0.08696 | 2.20878 | 1.66 | 42.16", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.20878", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "1\u00bc \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1 3/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 53.746\n\n**Minor diameter (mm):** 50.789\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1 3/4 | 1 3/4\" | 11 | 2.309 | 53.746 | 52.267 | 50.789\n\nSource: \n", "file": "1-3-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-3-4", "major_diameter_mm": "53.746", "minor_diameter_mm": "50.789", "nominal_size": "1 3/4", "source_quote": "BSPP G 1 3/4 | 1 3/4\" | 11 | 2.309 | 53.746 | 52.267 | 50.789", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "1 3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11 1/2\n\n**Thread pitch (mm):** 2.2087\n\n**Major (outside) diameter (mm):** 33.4010\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1.315 | 33.4010 |\n\nSource: \n", "file": "1-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-3", "major_diameter_mm": "33.4010", "nominal_size": "1", "source_quote": "1.315 | 33.4010 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.2087", "thread_standard": "NPT", "threads_per_inch": "11 1/2", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 13.157\n\n**Minor diameter (mm):** 11.445\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/4 | 19 | 0.0526 | 1.337 | 0.517 | 13.157 | 0.4506 | 11.445 | 0.2367 | 6.012\n\nSource: \n", "file": "1-4-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-4-2-2", "major_diameter_mm": "13.157", "minor_diameter_mm": "11.445", "nominal_size": "1/4", "source_quote": "1/4 | 19 | 0.0526 | 1.337 | 0.517 | 13.157 | 0.4506 | 11.445 | 0.2367 | 6.012", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSP", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 13.16\n\n**Minor diameter (mm):** 11.45\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> 13.16 | 12.30 | 11.45 | 0.104 | 11.5 | Rp | BSPT Rp 3/8 | 3/8\" | 19 | 1.337 | 6.4 | 0 | 16.66 | 15.81 | 14.95 | 0.104 | 15.0 | Rp | BSPT Rp 1/2 | 1/2\" | 14 | 1.814 | 8.2 | 0 | 20.96 | 19.79 | 18.63 | 0.142 | 18.5 | Rp | BSPT Rp 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 0 | 26.44 | 25.28 | 24.12 | 0.142 | 24.0 | Rp | BSPT Rp 1 | 1\" | 11 | 2.309 | 10.4 | 0 | 33.25 | 31.77 | 30.29 | 0.180 | 30.2 | Rp | BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:\n\nSource: \n", "file": "1-4-2-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-4-2-3", "major_diameter_mm": "13.16", "minor_diameter_mm": "11.45", "nominal_size": "1/4", "source_quote": "13.16 | 12.30 | 11.45 | 0.104 | 11.5 | Rp | BSPT Rp 3/8 | 3/8\" | 19 | 1.337 | 6.4 | 0 | 16.66 | 15.81 | 14.95 | 0.104 | 15.0 | Rp | BSPT Rp 1/2 | 1/2\" | 14 | 1.814 | 8.2 | 0 | 20.96 | 19.79 | 18.63 | 0.142 | 18.5 | Rp | BSPT Rp 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 0 | 26.44 | 25.28 | 24.12 | 0.142 | 24.0 | Rp | BSPT Rp 1 | 1\" | 11 | 2.309 | 10.4 | 0 | 33.25 | 31.77 | 30.29 | 0.180 | 30.2 | Rp | BSPT Rp 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 0 | 41.91 | 40.43 | 38.95 | 0.180 | 39.0 | Rp | BSPT Rp 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 0 | 47.80 | 46.32 | 44.85 | 0.180 | 45.0 | Rp | BSPT Rp 2 | 2\" | 11 | 2.309 | 15.9 | 0 | 59.61 | 58.14 | 56.66 | 0.180 | 56.4 | Rp | BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSPT", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 18\n\n**Thread pitch (mm):** 1.4111\n\n**Major (outside) diameter (mm):** 13.716\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 0.540 | 13.716 |\n\nSource: \n", "file": "1-4-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-4-2", "major_diameter_mm": "13.716", "nominal_size": "1/4", "source_quote": "0.540 | 13.716 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.4111", "thread_standard": "NPT", "threads_per_inch": "18", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 18\n\n**Thread pitch (mm):** 1.41122\n\n**Major (outside) diameter (mm):** 13.72\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1/4 | 18 | 0.05556 | 1.41122 | 0.54 | 13.72\n\nSource: \n", "file": "1-4-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-4-3", "major_diameter_mm": "13.72", "nominal_size": "1/4", "source_quote": "1/4 | 18 | 0.05556 | 1.41122 | 0.54 | 13.72", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.41122", "thread_standard": "NPT", "threads_per_inch": "18", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 13.157\n\n**Minor diameter (mm):** 11.445\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1/4 | 1/4\" | 19 | 1.337 | 13.157 | 12.301 | 11.445\n\nSource: \n", "file": "1-4-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-4-4", "major_diameter_mm": "13.157", "minor_diameter_mm": "11.445", "nominal_size": "1/4", "source_quote": "BSPP G 1/4 | 1/4\" | 19 | 1.337 | 13.157 | 12.301 | 11.445", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSPP", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/4 Inch BSP\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 13.16\n\n> 1/4 Inch BSP | 13.16 mm | 11.9mm | 19\n\nSource: \n", "file": "1-4-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-4-inch-bsp", "major_diameter_mm": "13.16", "nominal_size": "1/4 Inch BSP", "source_quote": "1/4 Inch BSP | 13.16 mm | 11.9mm | 19", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "1/4 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 13.157\n\n**Minor diameter (mm):** 11.445\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 |\n\nSource: \n", "file": "1-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-4", "major_diameter_mm": "13.157", "minor_diameter_mm": "11.445", "nominal_size": "1/4", "source_quote": "1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSP", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1\u00bd\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Thread pitch (mm):** 2.20878\n\n**Major (outside) diameter (mm):** 48.26\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1\u00bd | 11\u00bd | 0.08695 | 2.20878 | 1.9 | 48.26\n\nSource: \n", "file": "1-5.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-5", "major_diameter_mm": "48.26", "nominal_size": "1\u00bd", "source_quote": "1\u00bd | 11\u00bd | 0.08695 | 2.20878 | 1.9 | 48.26", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.20878", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "1\u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 33.249\n\n**Minor diameter (mm):** 30.292\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1 | 11 | 0.0909 | 2.309 | 1.309 | 33.249 | 1.1926 | 30.292 | 0.4091 | 10.391\n\nSource: \n", "file": "1-6.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-6", "major_diameter_mm": "33.249", "minor_diameter_mm": "30.292", "nominal_size": "1", "source_quote": "1 | 11 | 0.0909 | 2.309 | 1.309 | 33.249 | 1.1926 | 30.292 | 0.4091 | 10.391", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1\u00bc\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 41.91\n\n**Minor diameter (mm):** 38.953\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1\u00bc | 11 | 0.0909 | 2.309 | 1.65 | 41.91 | 1.5336 | 38.953 | 0.5 | 12.7\n\nSource: \n", "file": "1-7.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-7", "major_diameter_mm": "41.91", "minor_diameter_mm": "38.953", "nominal_size": "1\u00bc", "source_quote": "1\u00bc | 11 | 0.0909 | 2.309 | 1.65 | 41.91 | 1.5336 | 38.953 | 0.5 | 12.7", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1\u00bc \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 9.728\n\n**Minor diameter (mm):** 8.565\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/8 | 28 | 0.0357 | 0.907 | 0.383 | 9.728 | 0.3372 | 8.565 | 0.1563 | 3.97\n\nSource: \n", "file": "1-8-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-8-2-2", "major_diameter_mm": "9.728", "minor_diameter_mm": "8.565", "nominal_size": "1/8", "source_quote": "1/8 | 28 | 0.0357 | 0.907 | 0.383 | 9.728 | 0.3372 | 8.565 | 0.1563 | 3.97", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 9.73\n\n**Minor diameter (mm):** 8.57\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> 111.55 | 110.07 | 0 | -999.00 | R | BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00 | BSPT Rc (Internal Tapered) Dimensions Chart Dimensions are in millimeters . To view Inch values, click the Thread Description . The below chart shows only the main dimensions. To view all the dimensions, click the thread description or use the BSPT Thread Calculator . series | Thread | Pipe OD | TPI | Pitch | Gauge Length | Tol (Turns/mm) | Major Diam | Pitch Diam | Minor Diam | Fit Allowance (Turns/mm) | Tap Drill Size | Rc | BSPT Rc 1/16 | 1/16\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 7.72 | 7.14 | 6.56 | 0 | 6.4 | Rc | BSPT Rc 1/8 | 1/8\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 9.73 | 9.15 | 8.57 |\n\nSource: \n", "file": "1-8-2-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "1-8-2-3", "major_diameter_mm": "9.73", "minor_diameter_mm": "8.57", "nominal_size": "1/8", "source_quote": "111.55 | 110.07 | 0 | -999.00 | R | BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00 | BSPT Rc (Internal Tapered) Dimensions Chart Dimensions are in millimeters . To view Inch values, click the Thread Description . The below chart shows only the main dimensions. To view all the dimensions, click the thread description or use the BSPT Thread Calculator . series | Thread | Pipe OD | TPI | Pitch | Gauge Length | Tol (Turns/mm) | Major Diam | Pitch Diam | Minor Diam | Fit Allowance (Turns/mm) | Tap Drill Size | Rc | BSPT Rc 1/16 | 1/16\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 7.72 | 7.14 | 6.56 | 0 | 6.4 | Rc | BSPT Rc 1/8 | 1/8\" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 9.73 | 9.15 | 8.57 |", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSPT", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 27\n\n**Thread pitch (mm):** 0.9407\n\n**Major (outside) diameter (mm):** 10.287\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 0.405 | 10.287 |\n\nSource: \n", "file": "1-8-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-8-2", "major_diameter_mm": "10.287", "nominal_size": "1/8", "source_quote": "0.405 | 10.287 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "0.9407", "thread_standard": "NPT", "threads_per_inch": "27", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 27\n\n**Thread pitch (mm):** 0.94082\n\n**Major (outside) diameter (mm):** 10.29\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1/8 | 27 | 0.03704 | 0.94082 | 0.405 | 10.29\n\nSource: \n", "file": "1-8-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "1-8-3", "major_diameter_mm": "10.29", "nominal_size": "1/8", "source_quote": "1/8 | 27 | 0.03704 | 0.94082 | 0.405 | 10.29", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "0.94082", "thread_standard": "NPT", "threads_per_inch": "27", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 9.728\n\n**Minor diameter (mm):** 8.566\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 1/8 | 1/8\" | 28 | 0.907 | 9.728 | 9.147 | 8.566\n\nSource: \n", "file": "1-8-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-8-4", "major_diameter_mm": "9.728", "minor_diameter_mm": "8.566", "nominal_size": "1/8", "source_quote": "BSPP G 1/8 | 1/8\" | 28 | 0.907 | 9.728 | 9.147 | 8.566", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSPP", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/8 Inch BSP\n\n**Threads per inch (TPI):** 28\n\n**Major (outside) diameter (mm):** 9.7\n\n> 1/8 Inch BSP | 9.7 mm | 8.9 mm | 28\n\nSource: \n", "file": "1-8-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-8-inch-bsp", "major_diameter_mm": "9.7", "nominal_size": "1/8 Inch BSP", "source_quote": "1/8 Inch BSP | 9.7 mm | 8.9 mm | 28", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/8 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Thread pitch (mm):** 0.907\n\n**Major (outside) diameter (mm):** 9.728\n\n**Minor diameter (mm):** 8.566\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |\n\nSource: \n", "file": "1-8.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-8", "major_diameter_mm": "9.728", "minor_diameter_mm": "8.566", "nominal_size": "1/8", "source_quote": "1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "0.907", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1\u00bd\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 46.803\n\n**Minor diameter (mm):** 44.846\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1\u00bd | 11 | 0.0909 | 2.309 | 1.882 | 46.803 | 1.7656 | 44.846 | 0.5 | 12.7\n\nSource: \n", "file": "1-9.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1-9", "major_diameter_mm": "46.803", "minor_diameter_mm": "44.846", "nominal_size": "1\u00bd", "source_quote": "1\u00bd | 11 | 0.0909 | 2.309 | 1.882 | 46.803 | 1.7656 | 44.846 | 0.5 | 12.7", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1\u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1 Inch BSP\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 33.25\n\n> 1 Inch BSP | 33.25 mm | 31.0 mm | 11\n\nSource: \n", "file": "1-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "1-inch-bsp", "major_diameter_mm": "33.25", "nominal_size": "1 Inch BSP", "source_quote": "1 Inch BSP | 33.25 mm | 31.0 mm | 11", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 33.249\n\n**Minor diameter (mm):** 30.291\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |\n\nSource: \n", "file": "1.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "1", "major_diameter_mm": "33.249", "minor_diameter_mm": "30.291", "nominal_size": "1", "source_quote": "1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 10\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 273.0500\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 10.750 | 273.0500 |\n\nSource: \n", "file": "10.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "10", "major_diameter_mm": "273.0500", "nominal_size": "10", "source_quote": "10.750 | 273.0500 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "10 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 12\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 323.8500\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 12.750 | 323.8500 |\n\nSource: \n", "file": "12.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "12", "major_diameter_mm": "323.8500", "nominal_size": "12", "source_quote": "12.750 | 323.8500 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "12 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 2 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 75.18\n\n**Minor diameter (mm):** 72.23\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:\n\nSource: \n", "file": "2-1-2-2-2.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "2-1-2-2-2", "major_diameter_mm": "75.18", "minor_diameter_mm": "72.23", "nominal_size": "2 1/2", "source_quote": " BSPT Rp 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 0 | 75.18 | 73.71 | 72.23 | 0.216 | -999 | Rp | BSPT Rp 3 | 3\" | 11 | 2.309 | 20.6 | 0 | 87.88 | 86.41 | 84.93 | 0.216 | -999 | Rp | BSPT Rp 4 | 4\" | 11 | 2.309 | 25.4 | 0 | 113.03 | 111.55 | 110.07 | 0.216 | -999 | Rp | BSPT Rp 5 | 5\" | 11 | 2.309 | 28.6 | 0 | 138.43 | 136.95 | 135.47 | 0.216 | -999 | Rp | BSPT Rp 6 | 6\" | 11 | 2.309 | 28.6 | 0 | 163.83 | 162.35 | 160.87 | 0.216 | -999 | Tolerances and Inspection The ISO 7-1 provides tolerances only for the following dimensions:", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "2 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 2-1/2\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 73.0250\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 2.875 | 73.0250 |\n\nSource: \n", "file": "2-1-2-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "2-1-2-2", "major_diameter_mm": "73.0250", "nominal_size": "2-1/2", "source_quote": "2.875 | 73.0250 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "2-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 2 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 75.184\n\n**Minor diameter (mm):** 72.227\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 2 1/2 | 2 1/2\" | 11 | 2.309 | 75.184 | 73.705 | 72.227\n\nSource: \n", "file": "2-1-2-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-1-2-3", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.227", "nominal_size": "2 1/2", "source_quote": "BSPP G 2 1/2 | 2 1/2\" | 11 | 2.309 | 75.184 | 73.705 | 72.227", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "2 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2-1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 75.184\n\n**Minor diameter (mm):** 72.226\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 2\u00bd | 11 | 2.309 | 1.479 | 75.184 | 73.705 | 72.226 |\n\nSource: \n", "file": "2-1-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-1-2", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.226", "nominal_size": "2-1/2", "source_quote": "2\u00bd | 11 | 2.309 | 1.479 | 75.184 | 73.705 | 72.226 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_standard", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 2 1/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 65.710\n\n**Minor diameter (mm):** 62.753\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 2 1/4 | 2 1/4\" | 11 | 2.309 | 65.710 | 64.231 | 62.753\n\nSource: \n", "file": "2-1-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-1-4", "major_diameter_mm": "65.710", "minor_diameter_mm": "62.753", "nominal_size": "2 1/4", "source_quote": "BSPP G 2 1/4 | 2 1/4\" | 11 | 2.309 | 65.710 | 64.231 | 62.753", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "2 1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 2\u00bd\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.175\n\n**Major (outside) diameter (mm):** 73.03\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 2\u00bd | 8 | 0.125 | 3.175 | 2.875 | 73.03\n\nSource: \n", "file": "2-2-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "2-2-2", "major_diameter_mm": "73.03", "nominal_size": "2\u00bd", "source_quote": "2\u00bd | 8 | 0.125 | 3.175 | 2.875 | 73.03", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.175", "thread_standard": "NPT", "threads_per_inch": "8", "title": "2\u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11 1/2\n\n**Thread pitch (mm):** 2.2087\n\n**Major (outside) diameter (mm):** 60.3250\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 2.375 | 60.3250 |\n\nSource: \n", "file": "2-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "2-2", "major_diameter_mm": "60.3250", "nominal_size": "2", "source_quote": "2.375 | 60.3250 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.2087", "thread_standard": "NPT", "threads_per_inch": "11 1/2", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 2 3/4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 81.534\n\n**Minor diameter (mm):** 78.577\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 2 3/4 | 2 3/4\" | 11 | 2.309 | 81.534 | 80.055 | 78.577\n\nSource: \n", "file": "2-3-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-3-4", "major_diameter_mm": "81.534", "minor_diameter_mm": "78.577", "nominal_size": "2 3/4", "source_quote": "BSPP G 2 3/4 | 2 3/4\" | 11 | 2.309 | 81.534 | 80.055 | 78.577", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "2 3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Thread pitch (mm):** 2.20878\n\n**Major (outside) diameter (mm):** 60.33\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 2 | 11\u00bd | 0.08696 | 2.20878 | 2.375 | 60.33\n\nSource: \n", "file": "2-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "2-3", "major_diameter_mm": "60.33", "nominal_size": "2", "source_quote": "2 | 11\u00bd | 0.08696 | 2.20878 | 2.375 | 60.33", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "2.20878", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2\u00bd\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 75.184\n\n**Minor diameter (mm):** 72.227\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 2\u00bd | 11 | 0.0909 | 2.309 | 2.96 | 75.184 | 2.8436 | 72.227 | 0.6875 | 17.463\n\nSource: \n", "file": "2-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-4", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.227", "nominal_size": "2\u00bd", "source_quote": "2\u00bd | 11 | 0.0909 | 2.309 | 2.96 | 75.184 | 2.8436 | 72.227 | 0.6875 | 17.463", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2\u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 59.614\n\n**Minor diameter (mm):** 56.657\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 2 | 2\" | 11 | 2.309 | 59.614 | 58.135 | 56.657\n\nSource: \n", "file": "2-5.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2-5", "major_diameter_mm": "59.614", "minor_diameter_mm": "56.657", "nominal_size": "2", "source_quote": "BSPP G 2 | 2\" | 11 | 2.309 | 59.614 | 58.135 | 56.657", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2 Inch BSP\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 59.61\n\n> 2 Inch BSP | 59.61 mm | 57.4 mm | 11\n\nSource: \n", "file": "2-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "2-inch-bsp", "major_diameter_mm": "59.61", "nominal_size": "2 Inch BSP", "source_quote": "2 Inch BSP | 59.61 mm | 57.4 mm | 11", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 59.614\n\n**Minor diameter (mm):** 56.656\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 |\n\nSource: \n", "file": "2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "2", "major_diameter_mm": "59.614", "minor_diameter_mm": "56.656", "nominal_size": "2", "source_quote": "2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 3 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 100.330\n\n**Minor diameter (mm):** 97.373\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 3 1/2 | 3 1/2\" | 11 | 2.309 | 100.330 | 98.851 | 97.373\n\nSource: \n", "file": "3-1-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-1-2-2", "major_diameter_mm": "100.330", "minor_diameter_mm": "97.373", "nominal_size": "3 1/2", "source_quote": "BSPP G 3 1/2 | 3 1/2\" | 11 | 2.309 | 100.330 | 98.851 | 97.373", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "3 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3-1/2\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 101.6000\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 4.000 | 101.6000 |\n\nSource: \n", "file": "3-1-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-1-2", "major_diameter_mm": "101.6000", "nominal_size": "3-1/2", "source_quote": "4.000 | 101.6000 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "3-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 87.884\n\n**Minor diameter (mm):** 84.927\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3 | 11 | 0.0909 | 2.309 | 3.46 | 87.884 | 3.3436 | 84.927 | 0.8125 | 20.638\n\nSource: \n", "file": "3-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-2-2", "major_diameter_mm": "87.884", "minor_diameter_mm": "84.927", "nominal_size": "3", "source_quote": "3 | 11 | 0.0909 | 2.309 | 3.46 | 87.884 | 3.3436 | 84.927 | 0.8125 | 20.638", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 88.9000\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 3.500 | 88.9000 |\n\nSource: \n", "file": "3-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-2", "major_diameter_mm": "88.9000", "nominal_size": "3", "source_quote": "3.500 | 88.9000 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.175\n\n**Major (outside) diameter (mm):** 88.9\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 3 | 8 | 0.125 | 3.175 | 3.5 | 88.9\n\nSource: \n", "file": "3-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-3", "major_diameter_mm": "88.9", "nominal_size": "3", "source_quote": "3 | 8 | 0.125 | 3.175 | 3.5 | 88.9", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.175", "thread_standard": "NPT", "threads_per_inch": "8", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 26.441\n\n**Minor diameter (mm):** 24.12\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3/4 | 14 | 0.0714 | 1.814 | 1.041 | 26.441 | 0.9496 | 24.12 | 0.375 | 9.525\n\nSource: \n", "file": "3-4-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-4-2-2", "major_diameter_mm": "26.441", "minor_diameter_mm": "24.12", "nominal_size": "3/4", "source_quote": "3/4 | 14 | 0.0714 | 1.814 | 1.041 | 26.441 | 0.9496 | 24.12 | 0.375 | 9.525", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 26.44\n\n**Minor diameter (mm):** 24.12\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 1.0 / 1.8 | 26.44 | 25.28 | 24.12 | 0 | -999.00 | R | BSPT R 1 | 1\" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00 | R | BSPT R 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 1.0 / 2.3 | 41.91 | 40.43 | 38.95 | 0 | -999.00 | R | BSPT R 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 1.0 / 2.3 | 47.80 | 46.32 | 44.85 | 0 | -999.00 | R | BSPT R 2 | 2\" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00 | R | BSPT R 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 1.5 / 3.5 | 75.18 | 73.71 | 72.23 | 0 | -999.00 | R | BSPT R 3 | 3\" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00 | R | BSPT R 4 | 4\" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 |\n\nSource: \n", "file": "3-4-2-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "3-4-2-3", "major_diameter_mm": "26.44", "minor_diameter_mm": "24.12", "nominal_size": "3/4", "source_quote": " BSPT R 3/4 | 3/4\" | 14 | 1.814 | 9.5 | 1.0 / 1.8 | 26.44 | 25.28 | 24.12 | 0 | -999.00 | R | BSPT R 1 | 1\" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00 | R | BSPT R 1 1/4 | 1 1/4\" | 11 | 2.309 | 12.7 | 1.0 / 2.3 | 41.91 | 40.43 | 38.95 | 0 | -999.00 | R | BSPT R 1 1/2 | 1 1/2\" | 11 | 2.309 | 12.7 | 1.0 / 2.3 | 47.80 | 46.32 | 44.85 | 0 | -999.00 | R | BSPT R 2 | 2\" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00 | R | BSPT R 2 1/2 | 2 1/2\" | 11 | 2.309 | 17.5 | 1.5 / 3.5 | 75.18 | 73.71 | 72.23 | 0 | -999.00 | R | BSPT R 3 | 3\" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00 | R | BSPT R 4 | 4\" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 |", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPT", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.8143\n\n**Major (outside) diameter (mm):** 26.6700\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 1.050 | 26.6700 |\n\nSource: \n", "file": "3-4-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-4-2", "major_diameter_mm": "26.6700", "nominal_size": "3/4", "source_quote": "1.050 | 26.6700 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.8143", "thread_standard": "NPT", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.81432\n\n**Major (outside) diameter (mm):** 26.67\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 3/4 | 14 | 0.07143 | 1.81432 | 1.05 | 26.67\n\nSource: \n", "file": "3-4-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-4-3", "major_diameter_mm": "26.67", "nominal_size": "3/4", "source_quote": "3/4 | 14 | 0.07143 | 1.81432 | 1.05 | 26.67", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.81432", "thread_standard": "NPT", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 26.441\n\n**Minor diameter (mm):** 24.118\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 3/4 | 3/4\" | 14 | 1.814 | 26.441 | 25.279 | 24.118\n\nSource: \n", "file": "3-4-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-4-4", "major_diameter_mm": "26.441", "minor_diameter_mm": "24.118", "nominal_size": "3/4", "source_quote": "BSPP G 3/4 | 3/4\" | 14 | 1.814 | 26.441 | 25.279 | 24.118", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPP", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/4 Inch BSP\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 26.44\n\n> 3/4 Inch BSP | 26.44 mm | 24.6 mm | 14\n\nSource: \n", "file": "3-4-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "3-4-inch-bsp", "major_diameter_mm": "26.44", "nominal_size": "3/4 Inch BSP", "source_quote": "3/4 Inch BSP | 26.44 mm | 24.6 mm | 14", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "3/4 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 26.441\n\n**Minor diameter (mm):** 24.117\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |\n\nSource: \n", "file": "3-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-4", "major_diameter_mm": "26.441", "minor_diameter_mm": "24.117", "nominal_size": "3/4", "source_quote": "3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 87.884\n\n**Minor diameter (mm):** 84.927\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 3 | 3\" | 11 | 2.309 | 87.884 | 86.405 | 84.927\n\nSource: \n", "file": "3-5.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-5", "major_diameter_mm": "87.884", "minor_diameter_mm": "84.927", "nominal_size": "3", "source_quote": "BSPP G 3 | 3\" | 11 | 2.309 | 87.884 | 86.405 | 84.927", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 16.662\n\n**Minor diameter (mm):** 14.95\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3/8 | 19 | 0.0526 | 1.337 | 0.656 | 16.662 | 0.5886 | 14.95 | 0.25 | 6.25\n\nSource: \n", "file": "3-8-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-8-2-2", "major_diameter_mm": "16.662", "minor_diameter_mm": "14.95", "nominal_size": "3/8", "source_quote": "3/8 | 19 | 0.0526 | 1.337 | 0.656 | 16.662 | 0.5886 | 14.95 | 0.25 | 6.25", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSP", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 16.66\n\n**Minor diameter (mm):** 14.95\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 3/8 | 3/8\" | 19 | 1.337 | 6.4 | 1.0 / 1.3 | 16.66 | 15.81 | 14.95 |\n\nSource: \n", "file": "3-8-2-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "3-8-2-3", "major_diameter_mm": "16.66", "minor_diameter_mm": "14.95", "nominal_size": "3/8", "source_quote": " BSPT R 3/8 | 3/8\" | 19 | 1.337 | 6.4 | 1.0 / 1.3 | 16.66 | 15.81 | 14.95 |", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSPT", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 18\n\n**Thread pitch (mm):** 1.4111\n\n**Major (outside) diameter (mm):** 17.145\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 0.675 | 17.145 |\n\nSource: \n", "file": "3-8-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-8-2", "major_diameter_mm": "17.145", "nominal_size": "3/8", "source_quote": "0.675 | 17.145 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.4111", "thread_standard": "NPT", "threads_per_inch": "18", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 18\n\n**Thread pitch (mm):** 1.41122\n\n**Major (outside) diameter (mm):** 17.15\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 3/8 | 18 | 0.05556 | 1.41122 | 0.675 | 17.15\n\nSource: \n", "file": "3-8-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "3-8-3", "major_diameter_mm": "17.15", "nominal_size": "3/8", "source_quote": "3/8 | 18 | 0.05556 | 1.41122 | 0.675 | 17.15", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "1.41122", "thread_standard": "NPT", "threads_per_inch": "18", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 16.662\n\n**Minor diameter (mm):** 14.950\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 3/8 | 3/8\" | 19 | 1.337 | 16.662 | 15.806 | 14.950\n\nSource: \n", "file": "3-8-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-8-4", "major_diameter_mm": "16.662", "minor_diameter_mm": "14.950", "nominal_size": "3/8", "source_quote": "BSPP G 3/8 | 3/8\" | 19 | 1.337 | 16.662 | 15.806 | 14.950", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSPP", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/8 Inch BSP\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 16.66\n\n> 3/8 Inch BSP | 16.66 mm | 15.2 mm | 19\n\nSource: \n", "file": "3-8-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "3-8-inch-bsp", "major_diameter_mm": "16.66", "nominal_size": "3/8 Inch BSP", "source_quote": "3/8 Inch BSP | 16.66 mm | 15.2 mm | 19", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "3/8 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Thread pitch (mm):** 1.337\n\n**Major (outside) diameter (mm):** 16.662\n\n**Minor diameter (mm):** 14.950\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |\n\nSource: \n", "file": "3-8.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3-8", "major_diameter_mm": "16.662", "minor_diameter_mm": "14.950", "nominal_size": "3/8", "source_quote": "3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.337", "thread_standard": "BSP", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 87.884\n\n**Minor diameter (mm):** 84.926\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 |\n\nSource: \n", "file": "3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "3", "major_diameter_mm": "87.884", "minor_diameter_mm": "84.926", "nominal_size": "3", "source_quote": "3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 4 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 125.730\n\n**Minor diameter (mm):** 122.773\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 4 1/2 | 4 1/2\" | 11 | 2.309 | 125.730 | 124.251 | 122.773\n\nSource: \n", "file": "4-1-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "4-1-2", "major_diameter_mm": "125.730", "minor_diameter_mm": "122.773", "nominal_size": "4 1/2", "source_quote": "BSPP G 4 1/2 | 4 1/2\" | 11 | 2.309 | 125.730 | 124.251 | 122.773", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "4 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 113.03\n\n**Minor diameter (mm):** 110.073\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A\n\nSource: \n", "file": "4-2-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "4-2-2", "major_diameter_mm": "113.03", "minor_diameter_mm": "110.073", "nominal_size": "4", "source_quote": "4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 114.3000\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 4.500 | 114.3000 |\n\nSource: \n", "file": "4-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "4-2", "major_diameter_mm": "114.3000", "nominal_size": "4", "source_quote": "4.500 | 114.3000 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.175\n\n**Major (outside) diameter (mm):** 114.3\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 4 | 8 | 0.125 | 3.175 | 4.5 | 114.3\n\nSource: \n", "file": "4-3.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "4-3", "major_diameter_mm": "114.3", "nominal_size": "4", "source_quote": "4 | 8 | 0.125 | 3.175 | 4.5 | 114.3", "sources": ["https://www.geminivalve.com/bsp-thread-vs-npt-fitting/"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.175", "thread_standard": "NPT", "threads_per_inch": "8", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 113.030\n\n**Minor diameter (mm):** 110.073\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 4 | 4\" | 11 | 2.309 | 113.030 | 111.551 | 110.073\n\nSource: \n", "file": "4-4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "4-4", "major_diameter_mm": "113.030", "minor_diameter_mm": "110.073", "nominal_size": "4", "source_quote": "BSPP G 4 | 4\" | 11 | 2.309 | 113.030 | 111.551 | 110.073", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 113.030\n\n**Minor diameter (mm):** 110.072\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |\n\nSource: \n", "file": "4.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "4", "major_diameter_mm": "113.030", "minor_diameter_mm": "110.072", "nominal_size": "4", "source_quote": "4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 5 1/2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 151.130\n\n**Minor diameter (mm):** 148.173\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 5 1/2 | 5 1/2\" | 11 | 2.309 | 151.130 | 149.651 | 148.173\n\nSource: \n", "file": "5-1-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "5-1-2", "major_diameter_mm": "151.130", "minor_diameter_mm": "148.173", "nominal_size": "5 1/2", "source_quote": "BSPP G 5 1/2 | 5 1/2\" | 11 | 2.309 | 151.130 | 149.651 | 148.173", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "5 1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 5\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 138.430\n\n**Minor diameter (mm):** 135.472\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 5.4500 | 138.430\n\nSource: \n", "file": "5-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "5-2", "major_diameter_mm": "138.430", "minor_diameter_mm": "135.472", "nominal_size": "5", "source_quote": "5.4500 | 138.430", "sources": ["https://en.wikipedia.org/wiki/British_Standard_Pipe"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "5 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, minor_diameter_mm, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 5\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 138.430\n\n**Minor diameter (mm):** 135.473\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 5 | 5\" | 11 | 2.309 | 138.430 | 136.951 | 135.473\n\nSource: \n", "file": "5-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "5-3", "major_diameter_mm": "138.430", "minor_diameter_mm": "135.473", "nominal_size": "5", "source_quote": "BSPP G 5 | 5\" | 11 | 2.309 | 138.430 | 136.951 | 135.473", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "5 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 5/8\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 22.911\n\n**Minor diameter (mm):** 20.588\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 5/8 | 5/8\" | 14 | 1.814 | 22.911 | 21.749 | 20.588\n\nSource: \n", "file": "5-8-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "5-8-2", "major_diameter_mm": "22.911", "minor_diameter_mm": "20.588", "nominal_size": "5/8", "source_quote": "BSPP G 5/8 | 5/8\" | 14 | 1.814 | 22.911 | 21.749 | 20.588", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPP", "threads_per_inch": "14", "title": "5/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 5/8 Inch BSP\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 22.99\n\n> 5/8 Inch BSP | 22.99 mm | 20.3 mm | 14\n\nSource: \n", "file": "5-8-inch-bsp.md", "generated": true, "harvested": "2026-08-12", "id": "5-8-inch-bsp", "major_diameter_mm": "22.99", "nominal_size": "5/8 Inch BSP", "source_quote": "5/8 Inch BSP | 22.99 mm | 20.3 mm | 14", "sources": ["https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "5/8 Inch BSP \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 5/8\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 22.911\n\n**Minor diameter (mm):** 20.587\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 0.9020 | 22.911\n\nSource: \n", "file": "5-8.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "5-8", "major_diameter_mm": "22.911", "minor_diameter_mm": "20.587", "nominal_size": "5/8", "source_quote": "0.9020 | 22.911", "sources": ["https://en.wikipedia.org/wiki/British_Standard_Pipe"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "5/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, minor_diameter_mm, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 5\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 141.3002\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 5.563 | 141.3002 |\n\nSource: \n", "file": "5.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "5", "major_diameter_mm": "141.3002", "nominal_size": "5", "source_quote": "5.563 | 141.3002 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "5 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 6\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 168.2750\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 6.625 | 168.2750 |\n\nSource: \n", "file": "6-2.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "6-2", "major_diameter_mm": "168.2750", "nominal_size": "6", "source_quote": "6.625 | 168.2750 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "6 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 6\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 163.830\n\n**Minor diameter (mm):** 160.873\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 6 | 6\" | 11 | 2.309 | 163.830 | 162.351 | 160.873\n\nSource: \n", "file": "6-3.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "6-3", "major_diameter_mm": "163.830", "minor_diameter_mm": "160.873", "nominal_size": "6", "source_quote": "BSPP G 6 | 6\" | 11 | 2.309 | 163.830 | 162.351 | 160.873", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPP", "threads_per_inch": "11", "title": "6 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 6\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 163.830\n\n**Minor diameter (mm):** 160.872\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 6 | 11 | 2.309 | 1.479 | 163.830 | 162.351 | 160.872 |\n\nSource: \n", "file": "6.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "6", "major_diameter_mm": "163.830", "minor_diameter_mm": "160.872", "nominal_size": "6", "source_quote": "6 | 11 | 2.309 | 1.479 | 163.830 | 162.351 | 160.872 |", "sources": ["https://amesweb.info/Screws/BSP-Thread-Chart.aspx"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSP", "threads_per_inch": "11", "title": "6 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPP\n\n**Nominal size:** 7/8\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 30.201\n\n**Minor diameter (mm):** 27.878\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> BSPP G 7/8 | 7/8\" | 14 | 1.814 | 30.201 | 29.039 | 27.878\n\nSource: \n", "file": "7-8-2.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "7-8-2", "major_diameter_mm": "30.201", "minor_diameter_mm": "27.878", "nominal_size": "7/8", "source_quote": "BSPP G 7/8 | 7/8\" | 14 | 1.814 | 30.201 | 29.039 | 27.878", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSPP", "threads_per_inch": "14", "title": "7/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 7/8\n\n**Threads per inch (TPI):** 14\n\n**Thread pitch (mm):** 1.814\n\n**Major (outside) diameter (mm):** 30.201\n\n**Minor diameter (mm):** 27.877\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 228-1\n\n> 1.1890 | 30.201\n\nSource: \n", "file": "7-8.md", "generated": true, "governing_standard": "ISO 228-1", "harvested": "2026-08-12", "id": "7-8", "major_diameter_mm": "30.201", "minor_diameter_mm": "27.877", "nominal_size": "7/8", "source_quote": "1.1890 | 30.201", "sources": ["https://en.wikipedia.org/wiki/British_Standard_Pipe"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "1.814", "thread_standard": "BSP", "threads_per_inch": "14", "title": "7/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, minor_diameter_mm, nominal_size, thread_angle_degrees, thread_pitch_mm, thread_standard, threads_per_inch", "verified": false} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 8\n\n**Threads per inch (TPI):** 8\n\n**Thread pitch (mm):** 3.1750\n\n**Major (outside) diameter (mm):** 219.0750\n\n**Thread angle (degrees):** 60\n\n**Governing standard:** ASME B1.20.1\n\n> 8.625 | 219.0750 |\n\nSource: \n", "file": "8.md", "generated": true, "governing_standard": "ASME B1.20.1", "harvested": "2026-08-12", "id": "8", "major_diameter_mm": "219.0750", "nominal_size": "8", "source_quote": "8.625 | 219.0750 |", "sources": ["https://en.wikipedia.org/wiki/National_pipe_thread"], "stale_after": "2028-08-11", "thread_angle_degrees": "60", "thread_pitch_mm": "3.1750", "thread_standard": "NPT", "threads_per_inch": "8", "title": "8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees, thread_pitch_mm, thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/2\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 47.80\n\n> 1-1/2 Inch BSP | 47.80 mm / 1-3/4\" | 11\n\nSource: \n", "file": "bsp-1-1-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-1-2", "major_diameter_mm": "47.80", "nominal_size": "1-1/2", "source_quote": "1-1/2 Inch BSP | 47.80 mm / 1-3/4\" | 11", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1-1/4\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 41.91\n\n> 1-1/4 Inch BSP | 41.91 mm / 1.-1/2\" | 11\n\nSource: \n", "file": "bsp-1-1-4.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-1-4", "major_diameter_mm": "41.91", "nominal_size": "1-1/4", "source_quote": "1-1/4 Inch BSP | 41.91 mm / 1.-1/2\" | 11", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1-1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 20.8\n\n> -08 (1/2) | 14 | 20.8 | 0.82 | 19.1 | 0.75\n\nSource: \n", "file": "bsp-1-2-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-2-2", "major_diameter_mm": "20.8", "nominal_size": "1/2", "source_quote": "-08 (1/2) | 14 | 20.8 | 0.82 | 19.1 | 0.75", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 20.99\n\n> 1/2 Inch BSP | 20.99 mm / 3/4\" | 14\n\nSource: \n", "file": "bsp-1-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-2", "major_diameter_mm": "20.99", "nominal_size": "1/2", "source_quote": "1/2 Inch BSP | 20.99 mm / 3/4\" | 14", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1 \u00bc\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 41.9\n\n> -20 (1 \u00bc) | 11 | 41.9 | 1.65 | 39.6 | 1.56\n\nSource: \n", "file": "bsp-1-3.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-3", "major_diameter_mm": "41.9", "nominal_size": "1 \u00bc", "source_quote": "-20 (1 \u00bc) | 11 | 41.9 | 1.65 | 39.6 | 1.56", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 \u00bc \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 13.2\n\n> -04 (1/4) | 19 | 13.2 | 0.52 | 11.9 | 0.47\n\nSource: \n", "file": "bsp-1-4-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-4-2", "major_diameter_mm": "13.2", "nominal_size": "1/4", "source_quote": "-04 (1/4) | 19 | 13.2 | 0.52 | 11.9 | 0.47", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 13.16\n\n> 1/4 Inch BSP | 13.16 mm / 1/2\" | 19\n\nSource: \n", "file": "bsp-1-4.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-4", "major_diameter_mm": "13.16", "nominal_size": "1/4", "source_quote": "1/4 Inch BSP | 13.16 mm / 1/2\" | 19", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1 \u00bd\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 47.8\n\n> -24 (1 \u00bd) | 11 | 47.8 | 1.88 | 45.5 | 1.79\n\nSource: \n", "file": "bsp-1-5.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-5", "major_diameter_mm": "47.8", "nominal_size": "1 \u00bd", "source_quote": "-24 (1 \u00bd) | 11 | 47.8 | 1.88 | 45.5 | 1.79", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 \u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Major (outside) diameter (mm):** 9.7\n\n> -02 (1/8) | 28 | 9.7 | 0.38 | 8.9 | 0.35\n\nSource: \n", "file": "bsp-1-8-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-8-2", "major_diameter_mm": "9.7", "nominal_size": "1/8", "source_quote": "-02 (1/8) | 28 | 9.7 | 0.38 | 8.9 | 0.35", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 28\n\n**Major (outside) diameter (mm):** 9.52\n\n> 1/8 Inch BSP | 9.52 mm / 3/8\" | 28\n\nSource: \n", "file": "bsp-1-8.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1-8", "major_diameter_mm": "9.52", "nominal_size": "1/8", "source_quote": "1/8 Inch BSP | 9.52 mm / 3/8\" | 28", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "28", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 33.25\n\n> 1 Inch BSP | 33.25 mm / 1-1/4\" | 11\n\nSource: \n", "file": "bsp-1.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-1", "major_diameter_mm": "33.25", "nominal_size": "1", "source_quote": "1 Inch BSP | 33.25 mm / 1-1/4\" | 11", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 59.7\n\n> -32 (2) | 11 | 59.7 | 2.35 | 57.4 | 2.26\n\nSource: \n", "file": "bsp-2-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-2-2", "major_diameter_mm": "59.7", "nominal_size": "2", "source_quote": "-32 (2) | 11 | 59.7 | 2.35 | 57.4 | 2.26", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\n\n**Major (outside) diameter (mm):** 59.61\n\n> 2 Inch BSP | 59.61 mm / 2-1/4\" | 11\n\nSource: \n", "file": "bsp-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-2", "major_diameter_mm": "59.61", "nominal_size": "2", "source_quote": "2 Inch BSP | 59.61 mm / 2-1/4\" | 11", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "11", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 26.4\n\n> -12 (3/4) | 14 | 26.4 | 1.04 | 24.6 | 0.97\n\nSource: \n", "file": "bsp-3-4-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-3-4-2", "major_diameter_mm": "26.4", "nominal_size": "3/4", "source_quote": "-12 (3/4) | 14 | 26.4 | 1.04 | 24.6 | 0.97", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 26.44\n\n> 3/4 Inch BSP | 26.44 mm / 1\" | 14\n\nSource: \n", "file": "bsp-3-4.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-3-4", "major_diameter_mm": "26.44", "nominal_size": "3/4", "source_quote": "3/4 Inch BSP | 26.44 mm / 1\" | 14", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 16.5\n\n> -06 (3/8) | 19 | 16.5 | 0.65 | 15.2 | 0.60\n\nSource: \n", "file": "bsp-3-8-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-3-8-2", "major_diameter_mm": "16.5", "nominal_size": "3/8", "source_quote": "-06 (3/8) | 19 | 16.5 | 0.65 | 15.2 | 0.60", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 19\n\n**Major (outside) diameter (mm):** 16.66\n\n> 3/8 Inch BSP | 16.66 mm / 5/8\" | 19\n\nSource: \n", "file": "bsp-3-8.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-3-8", "major_diameter_mm": "16.66", "nominal_size": "3/8", "source_quote": "3/8 Inch BSP | 16.66 mm / 5/8\" | 19", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "19", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 5/8\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 22.4\n\n> -10 (5/8) | 14 | 22.4 | 0.88 | 20.3 | 0.80\n\nSource: \n", "file": "bsp-5-8-2.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-5-8-2", "major_diameter_mm": "22.4", "nominal_size": "5/8", "source_quote": "-10 (5/8) | 14 | 22.4 | 0.88 | 20.3 | 0.80", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "5/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSP\n\n**Nominal size:** 5/8\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 22.99\n\n> 5/8 Inch BSP | 22.99 mm / 7/8\" | 14\n\nSource: \n", "file": "bsp-5-8.md", "generated": true, "harvested": "2026-08-12", "id": "bsp-5-8", "major_diameter_mm": "22.99", "nominal_size": "5/8", "source_quote": "5/8 Inch BSP | 22.99 mm / 7/8\" | 14", "sources": ["https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings"], "stale_after": "2028-08-11", "thread_standard": "BSP", "threads_per_inch": "14", "title": "5/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 33.25\n\n**Minor diameter (mm):** 30.29\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 1 | 1\" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00\n\nSource: \n", "file": "bspt-1.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-1", "major_diameter_mm": "33.25", "minor_diameter_mm": "30.29", "nominal_size": "1", "source_quote": "BSPT R 1 | 1\" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 59.61\n\n**Minor diameter (mm):** 56.66\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 2 | 2\" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00\n\nSource: \n", "file": "bspt-2.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-2", "major_diameter_mm": "59.61", "minor_diameter_mm": "56.66", "nominal_size": "2", "source_quote": "BSPT R 2 | 2\" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 3\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 87.88\n\n**Minor diameter (mm):** 84.93\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 3 | 3\" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00\n\nSource: \n", "file": "bspt-3.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-3", "major_diameter_mm": "87.88", "minor_diameter_mm": "84.93", "nominal_size": "3", "source_quote": "BSPT R 3 | 3\" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "3 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 4\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 113.03\n\n**Minor diameter (mm):** 110.07\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 4 | 4\" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 | 110.07 | 0 | -999.00\n\nSource: \n", "file": "bspt-4.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-4", "major_diameter_mm": "113.03", "minor_diameter_mm": "110.07", "nominal_size": "4", "source_quote": "BSPT R 4 | 4\" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 | 110.07 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 5\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 138.43\n\n**Minor diameter (mm):** 135.47\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00\n\nSource: \n", "file": "bspt-5.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-5", "major_diameter_mm": "138.43", "minor_diameter_mm": "135.47", "nominal_size": "5", "source_quote": "BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "5 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** BSPT\n\n**Nominal size:** 6\n\n**Threads per inch (TPI):** 11\n\n**Thread pitch (mm):** 2.309\n\n**Major (outside) diameter (mm):** 163.83\n\n**Minor diameter (mm):** 160.87\n\n**Thread angle (degrees):** 55\n\n**Governing standard:** ISO 7-1\n\n> BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00\n\nSource: \n", "file": "bspt-6.md", "generated": true, "governing_standard": "ISO 7-1", "harvested": "2026-08-12", "id": "bspt-6", "major_diameter_mm": "163.83", "minor_diameter_mm": "160.87", "nominal_size": "6", "source_quote": "BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00", "sources": ["https://www.machiningdoctor.com/charts/bsp/"], "stale_after": "2028-08-11", "thread_angle_degrees": "55", "thread_pitch_mm": "2.309", "thread_standard": "BSPT", "threads_per_inch": "11", "title": "6 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "governing_standard, thread_angle_degrees", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/2\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 21.3\n\n> -08 (1/2) | 14 | 21.3 | 0.84 | 19.3 | 0.76\n\nSource: \n", "file": "npt-1-2.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1-2", "major_diameter_mm": "21.3", "nominal_size": "1/2", "source_quote": "-08 (1/2) | 14 | 21.3 | 0.84 | 19.3 | 0.76", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "14", "title": "1/2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1 \u00bc\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Major (outside) diameter (mm):** 42.2\n\n> -20 (1 \u00bc) | 11\u00bd | 42.2 | 1.66 | 40.1 | 1.58\n\nSource: \n", "file": "npt-1-3.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1-3", "major_diameter_mm": "42.2", "nominal_size": "1 \u00bc", "source_quote": "-20 (1 \u00bc) | 11\u00bd | 42.2 | 1.66 | 40.1 | 1.58", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "1 \u00bc \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/4\n\n**Threads per inch (TPI):** 18\n\n**Major (outside) diameter (mm):** 13.7\n\n> -04 (1/4) | 18 | 13.7 | 0.54 | 12.4 | 0.49\n\nSource: \n", "file": "npt-1-4.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1-4", "major_diameter_mm": "13.7", "nominal_size": "1/4", "source_quote": "-04 (1/4) | 18 | 13.7 | 0.54 | 12.4 | 0.49", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "18", "title": "1/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1 \u00bd\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Major (outside) diameter (mm):** 48.3\n\n> -24 (1 \u00bd) | 11\u00bd | 48.3 | 1.90 | 46.2 | 1.82\n\nSource: \n", "file": "npt-1-5.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1-5", "major_diameter_mm": "48.3", "nominal_size": "1 \u00bd", "source_quote": "-24 (1 \u00bd) | 11\u00bd | 48.3 | 1.90 | 46.2 | 1.82", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "1 \u00bd \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1/8\n\n**Threads per inch (TPI):** 27\n\n**Major (outside) diameter (mm):** 10.3\n\n> -02 (1/8) | 27 | 10.3 | 0.41 | 9.4 | 0.37\n\nSource: \n", "file": "npt-1-8.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1-8", "major_diameter_mm": "10.3", "nominal_size": "1/8", "source_quote": "-02 (1/8) | 27 | 10.3 | 0.41 | 9.4 | 0.37", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "27", "title": "1/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 1\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Major (outside) diameter (mm):** 33.3\n\n> -16 (1) | 11\u00bd | 33.3 | 1.31 | 31.5 | 1.24\n\nSource: \n", "file": "npt-1.md", "generated": true, "harvested": "2026-08-12", "id": "npt-1", "major_diameter_mm": "33.3", "nominal_size": "1", "source_quote": "-16 (1) | 11\u00bd | 33.3 | 1.31 | 31.5 | 1.24", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "1 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 2\n\n**Threads per inch (TPI):** 11\u00bd\n\n**Major (outside) diameter (mm):** 60.4\n\n> -32 (2) | 11\u00bd | 60.4 | 2.38 | 57.9 | 2.29\n\nSource: \n", "file": "npt-2.md", "generated": true, "harvested": "2026-08-12", "id": "npt-2", "major_diameter_mm": "60.4", "nominal_size": "2", "source_quote": "-32 (2) | 11\u00bd | 60.4 | 2.38 | 57.9 | 2.29", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "11\u00bd", "title": "2 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/4\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 26.9\n\n> -12 (3/4) | 14 | 26.9 | 1.06 | 24.9 | 0.98\n\nSource: \n", "file": "npt-3-4.md", "generated": true, "harvested": "2026-08-12", "id": "npt-3-4", "major_diameter_mm": "26.9", "nominal_size": "3/4", "source_quote": "-12 (3/4) | 14 | 26.9 | 1.06 | 24.9 | 0.98", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "14", "title": "3/4 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 3/8\n\n**Threads per inch (TPI):** 18\n\n**Major (outside) diameter (mm):** 17.3\n\n> -06 (3/8) | 18 | 17.3 | 0.68 | 15.7 | 0.62\n\nSource: \n", "file": "npt-3-8.md", "generated": true, "harvested": "2026-08-12", "id": "npt-3-8", "major_diameter_mm": "17.3", "nominal_size": "3/8", "source_quote": "-06 (3/8) | 18 | 17.3 | 0.68 | 15.7 | 0.62", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "18", "title": "3/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true} {"asset": "plumbing-fitting-thread-standards", "body": "**Thread standard:** NPT\n\n**Nominal size:** 5/8\n\n**Threads per inch (TPI):** 14\n\n**Major (outside) diameter (mm):** 22.9\n\n> -10 (5/8) | 14 | 22.9 | 0.90 | 21.1 | 0.83\n\nSource: \n", "file": "npt-5-8.md", "generated": true, "harvested": "2026-08-12", "id": "npt-5-8", "major_diameter_mm": "22.9", "nominal_size": "5/8", "source_quote": "-10 (5/8) | 14 | 22.9 | 0.90 | 21.1 | 0.83", "sources": ["https://trimantec.com/blogs/t/thread-identification-guide"], "stale_after": "2028-08-11", "thread_standard": "NPT", "threads_per_inch": "14", "title": "5/8 \u2014 Plumbing fitting and pipe thread standards", "type": "lookup", "unverified_fields": "thread_standard", "verified": true}