1/8
For 1/8, thread standard is BSPT; threads per inch (tpi) is 28; thread pitch (mm) is 0.907; major (outside) diameter (mm) is 9.73; minor diameter (mm) is 8.57, recorded from its source on 2026-08-12.
- Thread standard
- BSPT our reading
- Nominal size
- 1/8 verified
- Threads per inch (TPI)
- 28 verified
- Thread pitch (mm)
- 0.907 verified
- Major (outside) diameter (mm)
- 9.73 verified
- Minor diameter (mm)
- 8.57 verified
- Thread angle (degrees)
- 55 our reading
- Governing standard
- ISO 7-1 our reading
Values marked our reading are our classification of what the source says — the source does not print them in those words. The quote below is the evidence for each one; judge it yourself.
What the source says
111.55 | 110.07 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4513> BSPT R 5 | 5" | 11 | 2.309 | 28.6 | 1.5 / 3.5 | 138.43 | 136.95 | 135.47 | 0 | -999.00 | R | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4514> 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 <https://www.machiningdoctor.com/calculators/threading/?fam=BSPT&ser=Rc> 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 | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4515> 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 | <https://www.machiningdoctor.com/threadinfo-bspt/?tid=4516> BSPT Rc 1/8 | 1/8" | 28 | 0.907 | 4.0 | 1.25 / 1.1 | 9.73 | 9.15 | 8.57 |
— machiningdoctor.com, retrieved 2026-08-12
Source
- machiningdoctor.comhttps://www.machiningdoctor.com/charts/bsp/