4
For 4, thread standard is BSP; threads per inch (tpi) is 11; thread pitch (mm) is 2.309; major (outside) diameter (mm) is 113.030; minor diameter (mm) is 110.072, recorded from its source on 2026-08-12.
- Thread standard
- BSP our reading
- Nominal size
- 4 verified
- Threads per inch (TPI)
- 11 verified
- Thread pitch (mm)
- 2.309 verified
- Major (outside) diameter (mm)
- 113.030 verified
- Minor diameter (mm)
- 110.072 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
4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |
— amesweb.info, 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.
Major (outside) diameter (mm)
amesweb.info says major (outside) diameter (mm) is 113.030, as of 2026-08-12.
4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |
https://amesweb.info/Screws/BSP-Thread-Chart.aspx
geminivalve.com says major (outside) diameter (mm) is 113.03, as of 2026-08-12.
4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A
https://www.geminivalve.com/bsp-thread-vs-npt-fitting/
Minor diameter (mm)
amesweb.info says minor diameter (mm) is 110.072, as of 2026-08-12.
4 | 11 | 2.309 | 1.479 | 113.030 | 111.551 | 110.072 |
https://amesweb.info/Screws/BSP-Thread-Chart.aspx
geminivalve.com says minor diameter (mm) is 110.073, as of 2026-08-12.
4 | 11 | 0.0909 | 2.309 | 4.45 | 113.03 | 4.3336 | 110.073 | N/A | N/A
Sources
- amesweb.infohttps://amesweb.info/Screws/BSP-Thread-Chart.aspx
- geminivalve.comhttps://www.geminivalve.com/bsp-thread-vs-npt-fitting/