Reference Source

1-1/8

For 1-1/8, thread standard is BSP; threads per inch (tpi) is 11; thread pitch (mm) is 2.309; major (outside) diameter (mm) is 37.897; minor diameter (mm) is 34.939, recorded from its source on 2026-08-12.

Thread standard
BSP our reading
Nominal size
1-1/8
Threads per inch (TPI)
11
Thread pitch (mm)
2.309
Major (outside) diameter (mm)
37.897 verified
Minor diameter (mm)
34.939
Thread angle (degrees)
55 our reading
Governing standard
ISO 228-1 our reading
Sourceen.wikipedia.org
Verified
Review by
DatasetPlumbing fitting and pipe thread standards

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

1.4920 | 37.897

en.wikipedia.org, retrieved 2026-08-12

Source

Last verified against source: . Due for re-check by . This page as Markdown · OKF bundle · full dataset as JSON.