Unified Thread Standard (The US standards for threads per inch)
Major diameter (inches) | Threads per inch | ||
---|---|---|---|
Coarse (UNC) | Fine (UNF) | Extra fine (UNEF) | |
#0 = 0.0600 | 80 | ||
#1 = 0.0730 | 64 | 72 | |
#2 = 0.0860 | 56 | 64 | |
#3 = 0.0990 | 48 | 56 | |
#4 = 0.1120 | 40 | 48 | |
#5 = 0.1250 | 40 | 44 | |
#6 = 0.1380 | 32 | 40 | |
#8 = 0.1640 | 32 | 36 | |
#10 = 0.1900 | 24 | 32 | |
#12 = 0.2160 | 24 | 28 | 32 |
1/4 | 20 | 28 | 32 |
5/16 | 18 | 24 | 32 |
3/8 | 16 | 24 | 32 |
7/16 | 14 | 20 | 28 |
1/2 | 13 | 20 | 28 |
9/16 | 12 | 18 | 24 |
5/8 | 11 | 18 | 24 |
3/4 | 10 | 16 | 20 |
7/8 | 9 | 14 | 20 |
1 | 8 | 14* | 20 |