2½
For 2½, thread standard is BSP; threads per inch (tpi) is 11; thread pitch (mm) is 2.309; major (outside) diameter (mm) is 75.184; minor diameter (mm) is 72.227, recorded from its source on 2026-08-12.
- Thread standard
- BSP our reading
- Nominal size
- 2½ verified
- Threads per inch (TPI)
- 11 verified
- Thread pitch (mm)
- 2.309 verified
- Major (outside) diameter (mm)
- 75.184 verified
- Minor diameter (mm)
- 72.227 verified
- Thread angle (degrees)
- 55 our reading
- Governing standard
- ISO 228-1 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
2½ | 11 | 0.0909 | 2.309 | 2.96 | 75.184 | 2.8436 | 72.227 | 0.6875 | 17.463
— geminivalve.com, retrieved 2026-08-12
Source
- geminivalve.comhttps://www.geminivalve.com/bsp-thread-vs-npt-fitting/