1-1/4 Inch BSP
For 1-1/4 Inch BSP, thread standard is BSP; threads per inch (tpi) is 11; major (outside) diameter (mm) is 41.91, recorded from its source on 2026-08-12.
- Thread standard
- BSP our reading
- Nominal size
- 1-1/4 Inch BSP verified
- Threads per inch (TPI)
- 11 verified
- Major (outside) diameter (mm)
- 41.91 verified
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
1-1/4 Inch BSP | 41.91 mm | 39.6 mm | 11
— lsengineers.co.uk, retrieved 2026-08-12
Source
- lsengineers.co.ukhttps://www.lsengineers.co.uk/advice-centre/bsp-thread-sizes-explained