{ "name": "Plumbing fitting and pipe thread standards", "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.", "url": "https://referencesource.org/plumbing-fitting-thread-standards/", "licence": "factual compilation of thread dimensions from public reference sources; facts cited with attributed quotes, no standard document reproduced", "last_verified": "2026-08-12", "stale_after": "2028-08-11", "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" ], "records": [ { "thread_standard": "BSP", "nominal_size": "1", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "33.249", "minor_diameter_mm": "30.291", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "33.249", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |", "as_of": "2026-08-12" }, { "value": "33.249", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1 | 11 | 0.0909 | 2.309 | 1.309 | 33.249 | 1.1926 | 30.292 | 0.4091 | 10.391", "as_of": "2026-08-12" }, { "value": "33.25", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1 Inch BSP | 33.25 mm / 1-1/4\" | 11", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "30.291", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1 | 11 | 2.309 | 1.479 | 33.249 | 31.770 | 30.291 |", "as_of": "2026-08-12" }, { "value": "30.292", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1 | 11 | 0.0909 | 2.309 | 1.309 | 33.249 | 1.1926 | 30.292 | 0.4091 | 10.391", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSP", "nominal_size": "1-1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "47.803", "minor_diameter_mm": "44.845", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-2/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1\u00bd | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "47.803", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1\u00bd | 11 | 2.309 | 1.479 | 47.803 | 46.324 | 44.845 |", "as_of": "2026-08-12" }, { "value": "47.80", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1-1/2 Inch BSP | 47.80 mm / 1-3/4\" | 11", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1-1/2", "threads_per_inch": "11 1/2", "thread_pitch_mm": "2.2087", "major_diameter_mm": "48.2600", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-1-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.900 | 48.2600 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "1 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "47.80", "minor_diameter_mm": "44.85", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-1-2-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-2-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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:", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "47.803", "minor_diameter_mm": "44.846", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1 1/2 | 1 1/2\" | 11 | 2.309 | 47.803 | 46.324 | 44.846", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1-1/2 Inch BSP", "threads_per_inch": "11", "major_diameter_mm": "47.80", "id": "1-1-2-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-2-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1-1/2 Inch BSP | 47.80 mm | 45.5 mm | 11", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1-1/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "41.910", "minor_diameter_mm": "38.952", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-4/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1\u00bc | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "41.910", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1\u00bc | 11 | 2.309 | 1.479 | 41.910 | 40.431 | 38.952 |", "as_of": "2026-08-12" }, { "value": "41.91", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1-1/4 Inch BSP | 41.91 mm / 1.-1/2\" | 11", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1-1/4", "threads_per_inch": "11 1/2", "thread_pitch_mm": "2.2087", "major_diameter_mm": "42.1640", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-1-4-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.660 | 42.1640 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "1 1/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "41.91", "minor_diameter_mm": "38.95", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-1-4-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-2-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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:", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1 1/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "41.910", "minor_diameter_mm": "38.953", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-4-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1 1/4 | 1 1/4\" | 11 | 2.309 | 41.910 | 40.431 | 38.953", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1-1/4 Inch BSP", "threads_per_inch": "11", "major_diameter_mm": "41.91", "id": "1-1-4-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-4-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1-1/4 Inch BSP | 41.91 mm | 39.6 mm | 11", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1-1/8", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "37.897", "minor_diameter_mm": "34.939", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-8/", "source": "https://en.wikipedia.org/wiki/British_Standard_Pipe", "source_quote": "1.4920 | 37.897", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1 1/8", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "37.897", "minor_diameter_mm": "34.940", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-1-8-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-1-8-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1 1/8 | 1 1/8\" | 11 | 2.309 | 37.897 | 36.418 | 34.940", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "33.249", "minor_diameter_mm": "30.292", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-10", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-10/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1 | 1\" | 11 | 2.309 | 33.249 | 31.770 | 30.292", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/16", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "7.723", "minor_diameter_mm": "6.561", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-16", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-16/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/16 | 28 | 0.907 | 0.581 | 7.723 | 7.142 | 6.561 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "1/16", "threads_per_inch": "27", "thread_pitch_mm": "0.9407", "major_diameter_mm": "7.950", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-16-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-16-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.313 | 7.950 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "1/16", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "7.72", "minor_diameter_mm": "6.56", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-16-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-16-2-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1/16", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "7.723", "minor_diameter_mm": "6.561", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-16-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-16-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1/16 | 1/16\" | 28 | 0.907 | 7.723 | 7.142 | 6.561", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/2", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "20.955", "minor_diameter_mm": "18.631", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-2/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "20.955", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |", "as_of": "2026-08-12" }, { "value": "20.955", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/2 | 14 | 0.0714 | 1.814 | 0.825 | 20.955 | 0.7336 | 18.633 | 0.3214 | 8.164", "as_of": "2026-08-12" }, { "value": "20.99", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1/2 Inch BSP | 20.99 mm / 3/4\" | 14", "as_of": "2026-08-12" }, { "value": "20.8", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-08 (1/2) | 14 | 20.8 | 0.82 | 19.1 | 0.75", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "18.631", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/2 | 14 | 1.814 | 1.162 | 20.955 | 19.793 | 18.631 |", "as_of": "2026-08-12" }, { "value": "18.633", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/2 | 14 | 0.0714 | 1.814 | 0.825 | 20.955 | 0.7336 | 18.633 | 0.3214 | 8.164", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1/2", "threads_per_inch": "14", "thread_pitch_mm": "1.8143", "major_diameter_mm": "21.3360", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-2-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.840 | 21.3360 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "1.8143", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.840 | 21.3360 |", "as_of": "2026-08-12" }, { "value": "1.81432", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/2 | 14 | 0.07143 | 1.81432 | 0.84 | 21.34", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "21.3360", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.840 | 21.3360 |", "as_of": "2026-08-12" }, { "value": "21.34", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/2 | 14 | 0.07143 | 1.81432 | 0.84 | 21.34", "as_of": "2026-08-12" }, { "value": "21.3", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-08 (1/2) | 14 | 21.3 | 0.84 | 19.3 | 0.76", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPT", "nominal_size": "1/2", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "20.96", "minor_diameter_mm": "18.63", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-2-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-2-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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:", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1/2", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "20.955", "minor_diameter_mm": "18.632", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-2-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-2-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1/2 | 1/2\" | 14 | 1.814 | 20.955 | 19.793 | 18.632", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/2 Inch BSP", "threads_per_inch": "14", "major_diameter_mm": "20.99", "id": "1-2-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-2-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1/2 Inch BSP | 20.99 mm | 19.1 mm | 14", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "1", "threads_per_inch": "11 1/2", "thread_pitch_mm": "2.2087", "major_diameter_mm": "33.4010", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-3/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.315 | 33.4010 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "threads_per_inch", "versions": [ { "value": "11 1/2", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.315 | 33.4010 |", "as_of": "2026-08-12" }, { "value": "11\u00bd", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-16 (1) | 11\u00bd | 33.3 | 1.31 | 31.5 | 1.24", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "33.4010", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.315 | 33.4010 |", "as_of": "2026-08-12" }, { "value": "33.3", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-16 (1) | 11\u00bd | 33.3 | 1.31 | 31.5 | 1.24", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1\u00bc", "threads_per_inch": "11\u00bd", "thread_pitch_mm": "2.20878", "major_diameter_mm": "42.16", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-3-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-3-2/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1\u00bc | 11\u00bd | 0.08696 | 2.20878 | 1.66 | 42.16", "verified_fields": [ "major_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1 3/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "53.746", "minor_diameter_mm": "50.789", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-3-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-3-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1 3/4 | 1 3/4\" | 11 | 2.309 | 53.746 | 52.267 | 50.789", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/4", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "13.157", "minor_diameter_mm": "11.445", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-4/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "13.157", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/4 | 19 | 1.337 | 0.856 | 13.157 | 12.301 | 11.445 |", "as_of": "2026-08-12" }, { "value": "13.16", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1/4 Inch BSP | 13.16 mm / 1/2\" | 19", "as_of": "2026-08-12" }, { "value": "13.2", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-04 (1/4) | 19 | 13.2 | 0.52 | 11.9 | 0.47", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1/4", "threads_per_inch": "18", "thread_pitch_mm": "1.4111", "major_diameter_mm": "13.716", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-4-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-4-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.540 | 13.716 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "1.4111", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.540 | 13.716 |", "as_of": "2026-08-12" }, { "value": "1.41122", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/4 | 18 | 0.05556 | 1.41122 | 0.54 | 13.72", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "13.716", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.540 | 13.716 |", "as_of": "2026-08-12" }, { "value": "13.72", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/4 | 18 | 0.05556 | 1.41122 | 0.54 | 13.72", "as_of": "2026-08-12" }, { "value": "13.7", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-04 (1/4) | 18 | 13.7 | 0.54 | 12.4 | 0.49", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPT", "nominal_size": "1/4", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "13.16", "minor_diameter_mm": "11.45", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-4-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-4-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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:", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1/4", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "13.157", "minor_diameter_mm": "11.445", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-4-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-4-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1/4 | 1/4\" | 19 | 1.337 | 13.157 | 12.301 | 11.445", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/4 Inch BSP", "threads_per_inch": "19", "major_diameter_mm": "13.16", "id": "1-4-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-4-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1/4 Inch BSP | 13.16 mm | 11.9mm | 19", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "1\u00bd", "threads_per_inch": "11\u00bd", "thread_pitch_mm": "2.20878", "major_diameter_mm": "48.26", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-5/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1\u00bd | 11\u00bd | 0.08695 | 2.20878 | 1.9 | 48.26", "verified_fields": [ "major_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1\u00bc", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "41.91", "minor_diameter_mm": "38.953", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-7", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-7/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1\u00bc | 11 | 0.0909 | 2.309 | 1.65 | 41.91 | 1.5336 | 38.953 | 0.5 | 12.7", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/8", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "9.728", "minor_diameter_mm": "8.566", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-8/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "9.728", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |", "as_of": "2026-08-12" }, { "value": "9.728", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/8 | 28 | 0.0357 | 0.907 | 0.383 | 9.728 | 0.3372 | 8.565 | 0.1563 | 3.97", "as_of": "2026-08-12" }, { "value": "9.52", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "1/8 Inch BSP | 9.52 mm / 3/8\" | 28", "as_of": "2026-08-12" }, { "value": "9.7", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-02 (1/8) | 28 | 9.7 | 0.38 | 8.9 | 0.35", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "8.566", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "1/8 | 28 | 0.907 | 0.581 | 9.728 | 9.147 | 8.566 |", "as_of": "2026-08-12" }, { "value": "8.565", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/8 | 28 | 0.0357 | 0.907 | 0.383 | 9.728 | 0.3372 | 8.565 | 0.1563 | 3.97", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "1/8", "threads_per_inch": "27", "thread_pitch_mm": "0.9407", "major_diameter_mm": "10.287", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "1-8-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-8-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.405 | 10.287 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "0.9407", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.405 | 10.287 |", "as_of": "2026-08-12" }, { "value": "0.94082", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/8 | 27 | 0.03704 | 0.94082 | 0.405 | 10.29", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "10.287", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.405 | 10.287 |", "as_of": "2026-08-12" }, { "value": "10.29", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1/8 | 27 | 0.03704 | 0.94082 | 0.405 | 10.29", "as_of": "2026-08-12" }, { "value": "10.3", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-02 (1/8) | 27 | 10.3 | 0.41 | 9.4 | 0.37", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPT", "nominal_size": "1/8", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "9.73", "minor_diameter_mm": "8.57", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "1-8-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-8-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "1/8", "threads_per_inch": "28", "thread_pitch_mm": "0.907", "major_diameter_mm": "9.728", "minor_diameter_mm": "8.566", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-8-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-8-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 1/8 | 1/8\" | 28 | 0.907 | 9.728 | 9.147 | 8.566", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1/8 Inch BSP", "threads_per_inch": "28", "major_diameter_mm": "9.7", "id": "1-8-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-8-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1/8 Inch BSP | 9.7 mm | 8.9 mm | 28", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1\u00bd", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "46.803", "minor_diameter_mm": "44.846", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "1-9", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-9/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "1\u00bd | 11 | 0.0909 | 2.309 | 1.882 | 46.803 | 1.7656 | 44.846 | 0.5 | 12.7", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1 Inch BSP", "threads_per_inch": "11", "major_diameter_mm": "33.25", "id": "1-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/1-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "1 Inch BSP | 33.25 mm | 31.0 mm | 11", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "10", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "273.0500", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "10", "url": "https://referencesource.org/plumbing-fitting-thread-standards/10/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "10.750 | 273.0500 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "12", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "323.8500", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "12", "url": "https://referencesource.org/plumbing-fitting-thread-standards/12/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "12.750 | 323.8500 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "59.614", "minor_diameter_mm": "56.656", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "59.614", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "2 | 11 | 2.309 | 1.479 | 59.614 | 58.135 | 56.656 |", "as_of": "2026-08-12" }, { "value": "59.61", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "2 Inch BSP | 59.61 mm / 2-1/4\" | 11", "as_of": "2026-08-12" }, { "value": "59.7", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-32 (2) | 11 | 59.7 | 2.35 | 57.4 | 2.26", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSP", "nominal_size": "2-1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.226", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-1-2/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "2\u00bd | 11 | 2.309 | 1.479 | 75.184 | 73.705 | 72.226 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "2-1/2", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "73.0250", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "2-1-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "2.875 | 73.0250 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "2 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "75.18", "minor_diameter_mm": "72.23", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "2-1-2-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-2-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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:", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "2 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.227", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-1-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-1-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 2 1/2 | 2 1/2\" | 11 | 2.309 | 75.184 | 73.705 | 72.227", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "2 1/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "65.710", "minor_diameter_mm": "62.753", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-1-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-1-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 2 1/4 | 2 1/4\" | 11 | 2.309 | 65.710 | 64.231 | 62.753", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "2", "threads_per_inch": "11 1/2", "thread_pitch_mm": "2.2087", "major_diameter_mm": "60.3250", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "2.375 | 60.3250 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "threads_per_inch", "versions": [ { "value": "11 1/2", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "2.375 | 60.3250 |", "as_of": "2026-08-12" }, { "value": "11\u00bd", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "2 | 11\u00bd | 0.08696 | 2.20878 | 2.375 | 60.33", "as_of": "2026-08-12" }, { "value": "11\u00bd", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-32 (2) | 11\u00bd | 60.4 | 2.38 | 57.9 | 2.29", "as_of": "2026-08-12" } ] }, { "field": "thread_pitch_mm", "versions": [ { "value": "2.2087", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "2.375 | 60.3250 |", "as_of": "2026-08-12" }, { "value": "2.20878", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "2 | 11\u00bd | 0.08696 | 2.20878 | 2.375 | 60.33", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "60.3250", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "2.375 | 60.3250 |", "as_of": "2026-08-12" }, { "value": "60.33", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "2 | 11\u00bd | 0.08696 | 2.20878 | 2.375 | 60.33", "as_of": "2026-08-12" }, { "value": "60.4", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-32 (2) | 11\u00bd | 60.4 | 2.38 | 57.9 | 2.29", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "2\u00bd", "threads_per_inch": "8", "thread_pitch_mm": "3.175", "major_diameter_mm": "73.03", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "2-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-2-2/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "2\u00bd | 8 | 0.125 | 3.175 | 2.875 | 73.03", "verified_fields": [ "major_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "2 3/4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "81.534", "minor_diameter_mm": "78.577", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-3-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-3-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 2 3/4 | 2 3/4\" | 11 | 2.309 | 81.534 | 80.055 | 78.577", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "2\u00bd", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "75.184", "minor_diameter_mm": "72.227", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-4/", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "2\u00bd | 11 | 0.0909 | 2.309 | 2.96 | 75.184 | 2.8436 | 72.227 | 0.6875 | 17.463", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "59.614", "minor_diameter_mm": "56.657", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "2-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-5/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 2 | 2\" | 11 | 2.309 | 59.614 | 58.135 | 56.657", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "2 Inch BSP", "threads_per_inch": "11", "major_diameter_mm": "59.61", "id": "2-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/2-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "2 Inch BSP | 59.61 mm | 57.4 mm | 11", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "3", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "87.884", "minor_diameter_mm": "84.926", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "minor_diameter_mm", "versions": [ { "value": "84.926", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3 | 11 | 2.309 | 1.479 | 87.884 | 86.405 | 84.926 |", "as_of": "2026-08-12" }, { "value": "84.927", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3 | 11 | 0.0909 | 2.309 | 3.46 | 87.884 | 3.3436 | 84.927 | 0.8125 | 20.638", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "3-1/2", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "101.6000", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "3-1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-1-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "4.000 | 101.6000 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "3 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "100.330", "minor_diameter_mm": "97.373", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-1-2-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-1-2-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 3 1/2 | 3 1/2\" | 11 | 2.309 | 100.330 | 98.851 | 97.373", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "3", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "88.9000", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "3-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "3.500 | 88.9000 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "3.1750", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "3.500 | 88.9000 |", "as_of": "2026-08-12" }, { "value": "3.175", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3 | 8 | 0.125 | 3.175 | 3.5 | 88.9", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "88.9000", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "3.500 | 88.9000 |", "as_of": "2026-08-12" }, { "value": "88.9", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3 | 8 | 0.125 | 3.175 | 3.5 | 88.9", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSP", "nominal_size": "3/4", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "26.441", "minor_diameter_mm": "24.117", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-4/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "26.441", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |", "as_of": "2026-08-12" }, { "value": "26.441", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/4 | 14 | 0.0714 | 1.814 | 1.041 | 26.441 | 0.9496 | 24.12 | 0.375 | 9.525", "as_of": "2026-08-12" }, { "value": "26.44", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "3/4 Inch BSP | 26.44 mm / 1\" | 14", "as_of": "2026-08-12" }, { "value": "26.4", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-12 (3/4) | 14 | 26.4 | 1.04 | 24.6 | 0.97", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "24.117", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/4 | 14 | 1.814 | 1.162 | 26.441 | 25.279 | 24.117 |", "as_of": "2026-08-12" }, { "value": "24.12", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/4 | 14 | 0.0714 | 1.814 | 1.041 | 26.441 | 0.9496 | 24.12 | 0.375 | 9.525", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "3/4", "threads_per_inch": "14", "thread_pitch_mm": "1.8143", "major_diameter_mm": "26.6700", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "3-4-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-4-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.050 | 26.6700 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "1.8143", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.050 | 26.6700 |", "as_of": "2026-08-12" }, { "value": "1.81432", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/4 | 14 | 0.07143 | 1.81432 | 1.05 | 26.67", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "26.6700", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "1.050 | 26.6700 |", "as_of": "2026-08-12" }, { "value": "26.67", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/4 | 14 | 0.07143 | 1.81432 | 1.05 | 26.67", "as_of": "2026-08-12" }, { "value": "26.9", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-12 (3/4) | 14 | 26.9 | 1.06 | 24.9 | 0.98", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPT", "nominal_size": "3/4", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "26.44", "minor_diameter_mm": "24.12", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "3-4-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-4-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "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 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "3/4", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "26.441", "minor_diameter_mm": "24.118", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-4-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-4-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 3/4 | 3/4\" | 14 | 1.814 | 26.441 | 25.279 | 24.118", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "3/4 Inch BSP", "threads_per_inch": "14", "major_diameter_mm": "26.44", "id": "3-4-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-4-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "3/4 Inch BSP | 26.44 mm | 24.6 mm | 14", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "3", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "87.884", "minor_diameter_mm": "84.927", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-5/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 3 | 3\" | 11 | 2.309 | 87.884 | 86.405 | 84.927", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "3/8", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "16.662", "minor_diameter_mm": "14.950", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-8/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "16.662", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |", "as_of": "2026-08-12" }, { "value": "16.662", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/8 | 19 | 0.0526 | 1.337 | 0.656 | 16.662 | 0.5886 | 14.95 | 0.25 | 6.25", "as_of": "2026-08-12" }, { "value": "16.66", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "3/8 Inch BSP | 16.66 mm / 5/8\" | 19", "as_of": "2026-08-12" }, { "value": "16.5", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-06 (3/8) | 19 | 16.5 | 0.65 | 15.2 | 0.60", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "14.950", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "3/8 | 19 | 1.337 | 0.856 | 16.662 | 15.806 | 14.950 |", "as_of": "2026-08-12" }, { "value": "14.95", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/8 | 19 | 0.0526 | 1.337 | 0.656 | 16.662 | 0.5886 | 14.95 | 0.25 | 6.25", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "NPT", "nominal_size": "3/8", "threads_per_inch": "18", "thread_pitch_mm": "1.4111", "major_diameter_mm": "17.145", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "3-8-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-8-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.675 | 17.145 |", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "1.4111", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.675 | 17.145 |", "as_of": "2026-08-12" }, { "value": "1.41122", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/8 | 18 | 0.05556 | 1.41122 | 0.675 | 17.15", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "17.145", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "0.675 | 17.145 |", "as_of": "2026-08-12" }, { "value": "17.15", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "3/8 | 18 | 0.05556 | 1.41122 | 0.675 | 17.15", "as_of": "2026-08-12" }, { "value": "17.3", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-06 (3/8) | 18 | 17.3 | 0.68 | 15.7 | 0.62", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPT", "nominal_size": "3/8", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "16.66", "minor_diameter_mm": "14.95", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "3-8-2-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-8-2-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": " BSPT R 3/8 | 3/8\" | 19 | 1.337 | 6.4 | 1.0 / 1.3 | 16.66 | 15.81 | 14.95 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "3/8", "threads_per_inch": "19", "thread_pitch_mm": "1.337", "major_diameter_mm": "16.662", "minor_diameter_mm": "14.950", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "3-8-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-8-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 3/8 | 3/8\" | 19 | 1.337 | 16.662 | 15.806 | 14.950", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "3/8 Inch BSP", "threads_per_inch": "19", "major_diameter_mm": "16.66", "id": "3-8-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/3-8-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "3/8 Inch BSP | 16.66 mm | 15.2 mm | 19", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "113.030", "minor_diameter_mm": "110.072", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/4/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "113.030", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |", "as_of": "2026-08-12" }, { "value": "113.03", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A", "as_of": "2026-08-12" } ] }, { "field": "minor_diameter_mm", "versions": [ { "value": "110.072", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |", "as_of": "2026-08-12" }, { "value": "110.073", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPP", "nominal_size": "4 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "125.730", "minor_diameter_mm": "122.773", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "4-1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/4-1-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 4 1/2 | 4 1/2\" | 11 | 2.309 | 125.730 | 124.251 | 122.773", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "4", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "114.3000", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "4-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/4-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "4.500 | 114.3000 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "thread_pitch_mm", "versions": [ { "value": "3.1750", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "4.500 | 114.3000 |", "as_of": "2026-08-12" }, { "value": "3.175", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "4 | 8 | 0.125 | 3.175 | 4.5 | 114.3", "as_of": "2026-08-12" } ] }, { "field": "major_diameter_mm", "versions": [ { "value": "114.3000", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "4.500 | 114.3000 |", "as_of": "2026-08-12" }, { "value": "114.3", "source": "https://www.geminivalve.com/bsp-thread-vs-npt-fitting/", "source_quote": "4 | 8 | 0.125 | 3.175 | 4.5 | 114.3", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPP", "nominal_size": "4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "113.030", "minor_diameter_mm": "110.073", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "4-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/4-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 4 | 4\" | 11 | 2.309 | 113.030 | 111.551 | 110.073", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "5", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "141.3002", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "5.563 | 141.3002 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "5 1/2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "151.130", "minor_diameter_mm": "148.173", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "5-1-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-1-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 5 1/2 | 5 1/2\" | 11 | 2.309 | 151.130 | 149.651 | 148.173", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "5", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "138.430", "minor_diameter_mm": "135.472", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "5-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-2/", "source": "https://en.wikipedia.org/wiki/British_Standard_Pipe", "source_quote": "5.4500 | 138.430", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "5", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "138.430", "minor_diameter_mm": "135.473", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "5-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 5 | 5\" | 11 | 2.309 | 138.430 | 136.951 | 135.473", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "5/8", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "22.911", "minor_diameter_mm": "20.587", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "5-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-8/", "source": "https://en.wikipedia.org/wiki/British_Standard_Pipe", "source_quote": "0.9020 | 22.911", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ], "disagreements": [ { "field": "major_diameter_mm", "versions": [ { "value": "22.911", "source": "https://en.wikipedia.org/wiki/British_Standard_Pipe", "source_quote": "0.9020 | 22.911", "as_of": "2026-08-12" }, { "value": "22.99", "source": "https://www.htsspares.com/blog/how-to/how-to-measure-your-bsp-fittings", "source_quote": "5/8 Inch BSP | 22.99 mm / 7/8\" | 14", "as_of": "2026-08-12" }, { "value": "22.4", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-10 (5/8) | 14 | 22.4 | 0.88 | 20.3 | 0.80", "as_of": "2026-08-12" } ] } ] }, { "thread_standard": "BSPP", "nominal_size": "5/8", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "22.911", "minor_diameter_mm": "20.588", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "5-8-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-8-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 5/8 | 5/8\" | 14 | 1.814 | 22.911 | 21.749 | 20.588", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "5/8 Inch BSP", "threads_per_inch": "14", "major_diameter_mm": "22.99", "id": "5-8-inch-bsp", "url": "https://referencesource.org/plumbing-fitting-thread-standards/5-8-inch-bsp/", "source": "https://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained", "source_quote": "5/8 Inch BSP | 22.99 mm | 20.3 mm | 14", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "6", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "163.830", "minor_diameter_mm": "160.872", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "6", "url": "https://referencesource.org/plumbing-fitting-thread-standards/6/", "source": "https://amesweb.info/Screws/BSP-Thread-Chart.aspx", "source_quote": "6 | 11 | 2.309 | 1.479 | 163.830 | 162.351 | 160.872 |", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "6", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "168.2750", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "6-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/6-2/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "6.625 | 168.2750 |", "verified_fields": [ "major_diameter_mm", "nominal_size" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "6", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "163.830", "minor_diameter_mm": "160.873", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "6-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/6-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 6 | 6\" | 11 | 2.309 | 163.830 | 162.351 | 160.873", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "7/8", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "30.201", "minor_diameter_mm": "27.877", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "7-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/7-8/", "source": "https://en.wikipedia.org/wiki/British_Standard_Pipe", "source_quote": "1.1890 | 30.201", "verified_fields": [ "major_diameter_mm" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPP", "nominal_size": "7/8", "threads_per_inch": "14", "thread_pitch_mm": "1.814", "major_diameter_mm": "30.201", "minor_diameter_mm": "27.878", "thread_angle_degrees": "55", "governing_standard": "ISO 228-1", "id": "7-8-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/7-8-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPP G 7/8 | 7/8\" | 14 | 1.814 | 30.201 | 29.039 | 27.878", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "8", "threads_per_inch": "8", "thread_pitch_mm": "3.1750", "major_diameter_mm": "219.0750", "thread_angle_degrees": "60", "governing_standard": "ASME B1.20.1", "id": "8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/8/", "source": "https://en.wikipedia.org/wiki/National_pipe_thread", "source_quote": "8.625 | 219.0750 |", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1 \u00bc", "threads_per_inch": "11", "major_diameter_mm": "41.9", "id": "bsp-1-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bsp-1-3/", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-20 (1 \u00bc) | 11 | 41.9 | 1.65 | 39.6 | 1.56", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSP", "nominal_size": "1 \u00bd", "threads_per_inch": "11", "major_diameter_mm": "47.8", "id": "bsp-1-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bsp-1-5/", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-24 (1 \u00bd) | 11 | 47.8 | 1.88 | 45.5 | 1.79", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "1", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "33.25", "minor_diameter_mm": "30.29", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-1", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-1/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 1 | 1\" | 11 | 2.309 | 10.4 | 1.0 / 2.3 | 33.25 | 31.77 | 30.29 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "2", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "59.61", "minor_diameter_mm": "56.66", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-2", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-2/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 2 | 2\" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "3", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "87.88", "minor_diameter_mm": "84.93", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-3/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 3 | 3\" | 11 | 2.309 | 20.6 | 1.5 / 3.5 | 87.88 | 86.41 | 84.93 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "4", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "113.03", "minor_diameter_mm": "110.07", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-4", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-4/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 4 | 4\" | 11 | 2.309 | 25.4 | 1.5 / 3.5 | 113.03 | 111.55 | 110.07 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "5", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "138.43", "minor_diameter_mm": "135.47", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-5/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 5 | 5\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "BSPT", "nominal_size": "6", "threads_per_inch": "11", "thread_pitch_mm": "2.309", "major_diameter_mm": "163.83", "minor_diameter_mm": "160.87", "thread_angle_degrees": "55", "governing_standard": "ISO 7-1", "id": "bspt-6", "url": "https://referencesource.org/plumbing-fitting-thread-standards/bspt-6/", "source": "https://www.machiningdoctor.com/charts/bsp/", "source_quote": "BSPT R 6 | 6\" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 163.83 | 162.35 | 160.87 | 0 | -999.00", "verified_fields": [ "major_diameter_mm", "minor_diameter_mm", "nominal_size", "thread_pitch_mm", "threads_per_inch" ], "derived_fields": [ "governing_standard", "thread_angle_degrees", "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "1 \u00bc", "threads_per_inch": "11\u00bd", "major_diameter_mm": "42.2", "id": "npt-1-3", "url": "https://referencesource.org/plumbing-fitting-thread-standards/npt-1-3/", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-20 (1 \u00bc) | 11\u00bd | 42.2 | 1.66 | 40.1 | 1.58", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "1 \u00bd", "threads_per_inch": "11\u00bd", "major_diameter_mm": "48.3", "id": "npt-1-5", "url": "https://referencesource.org/plumbing-fitting-thread-standards/npt-1-5/", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-24 (1 \u00bd) | 11\u00bd | 48.3 | 1.90 | 46.2 | 1.82", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] }, { "thread_standard": "NPT", "nominal_size": "5/8", "threads_per_inch": "14", "major_diameter_mm": "22.9", "id": "npt-5-8", "url": "https://referencesource.org/plumbing-fitting-thread-standards/npt-5-8/", "source": "https://trimantec.com/blogs/t/thread-identification-guide", "source_quote": "-10 (5/8) | 14 | 22.9 | 0.90 | 21.1 | 0.83", "verified_fields": [ "major_diameter_mm", "nominal_size", "threads_per_inch" ], "derived_fields": [ "thread_standard" ] } ] }