Thread Designations

UNC
= Unified Course
UNF
= Unified Fine
UNS
= Unified Special
UNEF
= Unified Extra Fine

Thread Major (Outside) Diameter Minor (Inside) Diameter Peak-to-Peak Pitch Dimension
Designation (Male Threads) (Female Threads) Pitch Dimension Parts with Listed Thread
6-32 UNG 0.135 0.106 0.031 PO509, PO516
8-32 UNG 0.16 0.135 0.031 GE757, PO5060
10-32UNF 0.187 0.161 0.031 PO528, PO529
12-28 UNF 0.213 0.181 0.036 PS677
.236-32 UNS 0.234 0.197 0.031 P0582
6mm - .75 0.234 0.197 0.029 P0577
1/4-40 UNS 0.246 0.226 0.025 P0504
1/4-28 UNF 0.246 0.215 0.036 P0506,P0507,P0508,PS691
.265-36 UNS 0.262 0.236 0.028 PO501,PO502
1/16-27 NPT 0.313 0.246 0.037 PO561
5/16-32 UNEF 0.308 0.283 0.031 BA717, BA721, GE754, GE755, P0512, P0527, P0533, P0568, RS812
5/16-27 UNS 0.308 0.278 0.037 BJ214,BJ215, BJ220,GF509,GF639, P0530,PS692
5/16-24 UNF 0.308 0.272 0.042 BJ214,BJ215, BJ220,GF509,GF639, P0530,PS692
5/16-18 UNG 0.308 0.257 0.056 PO544
11/32-32 UNS 0.34 0.299 0.031 P0518,P0567,P0569,P0575
11/32-27 UNS 0.34 0.299 0.037 PO531
3/8-40 UNS 0.37 0.351 0.025 CO402, CO409
11/32-27 UNS 0.34 0.299 0.037 PO531
3/8-40 UNS 0.37 0.351 0.025 CO402, CO409
3/8-32 UNEF 0.37 0.345 0.031 PO538
3/8-27 UNS 0.37 0.34 0.037 C0400, C0403, C0406, C0407, C0408, C0414,C0417,P0536,P0573
3/8-24 UNF 0.37 0.339 0.042 BA701, BA702, BA703, BA713, BA715, BA718, BA719, G0415, MH850, MH851, MH852, MH853, MH854, MH855, P0511, PS675, PS676
7/16-27 UNS 0.433 0.402 0.037 BA715, BA716, BA718, BA721, BJ217, BJ218, BJ232, CF511, GF614, CF641, CF642, CF643, GE751, GE752, GE754, GE755, GE756, MH851, MH854, MH855, P0541, P0543, PS650, PS691, RS829, WR900, WR902, WR903, WR906, PS693, PS698, RS819, RS827, RS828,
7/16-24 UNS 0.433 0.397 0.042 WR903,WR904,WR905,WR906
7/16-20 UNF 0.433 0.383 0.05 CO404,PO555,P0556
1/2-24 UNS 0.491 0.46 0.042 CF512,PO554
1/2-20 UNF 0.491 0.451 0.05 CO405,PO553,WR900,WR901,2R902
1/4-18 NPT 0.54 0.438 0.056 OB205, 0B207, OB208, PO520, PO525, PO592
9/16-17 UNS 0.555 0.527 0.037 BJ231,-0558
9/16-24 UNEF 0.555 0.522 0.042 CF513,CF644
9/16-18 UNF 0.555 0.509 0.056 P0557
9/16-24 UNEF 0.555 0.522 0.042 C0410
5/8-27 UNS 0.621 0.59 0.037 P0559
5/8-24 UNEF 0.621 0.585 0.042 CF645
5/8-18 UNF 0.621 0.572 0.056 BJ234, P0532
3/8-18 NPT 0.675 0.578 0.056 P0521,P0593
3/4-27 UNS 0.745 0.715 0.037 P0535
3/4-16 UNF 0.745 0.689 0.063 P0534
1/2-14 NPT 0.84 0.719 0.071 P0522