# 2 — Plumbing fitting and pipe thread standards For 2, thread standard is BSPT; threads per inch (tpi) is 11; thread pitch (mm) is 2.309; major (outside) diameter (mm) is 59.61; minor diameter (mm) is 56.66, recorded from its source on 2026-08-12. - **Thread standard:** BSPT _(our reading, not quoted from the source)_ - **Nominal size:** 2 _(verified: appears in the quote below)_ - **Threads per inch (TPI):** 11 _(verified: appears in the quote below)_ - **Thread pitch (mm):** 2.309 _(verified: appears in the quote below)_ - **Major (outside) diameter (mm):** 59.61 _(verified: appears in the quote below)_ - **Minor diameter (mm):** 56.66 _(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 > BSPT R 2 | 2" | 11 | 2.309 | 15.9 | 1.0 / 2.3 | 59.61 | 58.14 | 56.66 | 0 | -999.00 ## 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/).