US Thread Per Inch Flange Bolt

Threads Per Inch (TPI)

Coarse ThreadFine Thread
Bolt SizeUNCUNF
#0000160
#000120
#0090
#080
#16472
#25664
#34856
#44048
#54044
#63240
#83236
#102432
#122428
1/4″2028
5/16″1824
3/8″1624
7/16″1420
1/2″1320
9/16″1218
5/8″1118
3/4″1016
7/8″914
1″812*
1-1/8″712
1-1/4″712
1-1/2″612
* 12tpi is the UNF standard however 14tpi is far more common in actual use.