# 1/16 — Plumbing fitting and pipe thread standards For 1/16, thread standard is BSPT; threads per inch (tpi) is 28; thread pitch (mm) is 0.907; major (outside) diameter (mm) is 7.72; minor diameter (mm) is 6.56, recorded from its source on 2026-08-12. - **Thread standard:** BSPT _(our reading, not quoted from the source)_ - **Nominal size:** 1/16 _(verified: appears in the quote below)_ - **Threads per inch (TPI):** 28 _(verified: appears in the quote below)_ - **Thread pitch (mm):** 0.907 _(verified: appears in the quote below)_ - **Major (outside) diameter (mm):** 7.72 _(verified: appears in the quote below)_ - **Minor diameter (mm):** 6.56 _(verified: appears in the quote below)_ - **Thread angle (degrees):** 55 _(our reading, not quoted from the source)_ - **Governing standard:** ISO 7-1 _(our reading, not quoted from the source)_ ## What the source says > 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 | ## Source - https://www.machiningdoctor.com/charts/bsp/ Last verified: 2026-08-12. Review by: 2028-08-11. Part of [Plumbing fitting and pipe thread standards](https://referencesource.org/plumbing-fitting-thread-standards/).