ASME Unified National Coarse (UNC)

All 33 thread sizes per ASME B1.1. Click any row for full specifications, tolerances, and geometry.

DesignationDiameter (in)TPISpecs
#10.07364 TPI
#20.08656 TPI
#30.09948 TPI
#40.11240 TPI
#50.12540 TPI
#60.13832 TPI
#80.16432 TPI
#100.1924 TPI
#120.21624 TPI
1/4"0.2520 TPI
5/16"0.312518 TPI
3/8"0.37516 TPI
7/16"0.437514 TPI
1/2"0.513 TPI
9/16"0.562512 TPI
5/8"0.62511 TPI
3/4"0.7510 TPI
7/8"0.8759 TPI
1"18 TPI
1 1/8"1.1257 TPI
1 1/4"1.257 TPI
1 3/8"1.3756 TPI
1 1/2"1.56 TPI
1 3/4"1.755 TPI
2"24.5 TPI
2 1/4"2.254.5 TPI
2 1/2"2.54 TPI
2 3/4"2.754 TPI
3"34 TPI
3 1/4"3.254 TPI
3 1/2"3.54 TPI
3 3/4"3.754 TPI
4"44 TPI

Showing 33 thread sizes • Standards: ASME B1.1