4
For 4, thread standard is NPT; threads per inch (tpi) is 8; thread pitch (mm) is 3.1750; major (outside) diameter (mm) is 114.3000; thread angle (degrees) is 60, recorded from its source on 2026-08-12.
- Thread standard
- NPT our reading
- Nominal size
- 4 verified
- Threads per inch (TPI)
- 8
- Thread pitch (mm)
- 3.1750
- Major (outside) diameter (mm)
- 114.3000 verified
- Thread angle (degrees)
- 60 our reading
- Governing standard
- ASME B1.20.1 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
4.500 | 114.3000 |
— en.wikipedia.org, retrieved 2026-08-12
Sources disagree
More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.
Thread pitch (mm)
en.wikipedia.org says thread pitch (mm) is 3.1750, as of 2026-08-12.
4.500 | 114.3000 |
https://en.wikipedia.org/wiki/National_pipe_thread
geminivalve.com says thread pitch (mm) is 3.175, as of 2026-08-12.
4 | 8 | 0.125 | 3.175 | 4.5 | 114.3
https://www.geminivalve.com/bsp-thread-vs-npt-fitting/
Major (outside) diameter (mm)
en.wikipedia.org says major (outside) diameter (mm) is 114.3000, as of 2026-08-12.
4.500 | 114.3000 |
https://en.wikipedia.org/wiki/National_pipe_thread
geminivalve.com says major (outside) diameter (mm) is 114.3, as of 2026-08-12.
4 | 8 | 0.125 | 3.175 | 4.5 | 114.3
Sources
- en.wikipedia.orghttps://en.wikipedia.org/wiki/National_pipe_thread
- geminivalve.comhttps://www.geminivalve.com/bsp-thread-vs-npt-fitting/