Thread geometry – Unified Fine (UNF)

All dimensions in inch unless otherwise stated.

d1 – Minor thread diameter male

d2 – Minor thread diameter female

d3 – Pitch diameter

d4 – Major diameter
Thread Major diameter Thread per inch Pitch diameter Minor diameter male thread Minor diameter female thread
0 0.0600 80 0.0519 0.0451 0.0465
1 0.0730 72 0.0640 0.0565 0.0580
2 0.0860 64 0.0759 0.0674 0.0691
3 0.0990 56 0.0874 0.0778 0.0797
4 0.1120 48 0.0985 0.0871 0.0894
5 0.1250 44 0.1102 0.0979 0.1004
6 0.1380 40 0.1218 0.1082 0.1109
8 0.1640 36 0.1460 0.1309 0.1339
10 0.1900 32 0.1697 0.1528 0.1562
12 0.2160 28 0.1928 0.1734 0.1773
Thread Major diameter Thread per inch Pitch diameter Minor diameter male thread Minor diameter female thread
1/4 0.2500 28 0.2268 0.2074 0.2113
5/16 0.3125 24 0.2854 0.2629 0.2674
3/8 0.3750 24 0.3479 0.3254 0.3299
7/16 0.4375 20 0.4050 0.3780 0.3834
1/2 0.5000 20 0.4675 0.4405 0.4459
9/16 0.5625 18 0.5264 0.4964 0.5024
5/8 0.6250 18 0.5889 0.5589 0.5649
3/4 0.7500 16 0.7094 0.6763 0.6823
7/8 0.8750 14 0.8286 0.7900 0.7977
1 1.0000 12 0.9459 0.9001 0.9098
Thread Major diameter Thread per inch Pitch diameter Minor diameter male thread Minor diameter female thread
1 1/8 1.1250 12 1.0709 1.0258 1.0348
1 1/4 1.2500 12 1.1959 1.1508 1.1598
1 3/8 1.3750 12 1.3209 1.2758 1.2848
1 1/2 1.5000 12 1.4459 1.4008 1.4098