ASME B1.20.1 Pipe Threads: NPTR (taper, railing)

All 10 thread sizes per ASME B1.20.1. Click any row for full specifications, tolerances, and geometry.

DesignationDiameter (in)TPISpecs
1/2"0.8414 TPI
3/4"1.0514 TPI
1"1.31511.5 TPI
1-1/4"1.6611.5 TPI
1-1/2"1.911.5 TPI
2"2.37511.5 TPI
2-1/2"2.8758 TPI
3"3.58 TPI
3-1/2"48 TPI
4"4.58 TPI

Showing 10 thread sizes • Standards: ASME B1.20.1