The pitch of a fastener refers to the distance between threads. This guide explains the different pitches available at different sizes of imperial fastener.
| Diameter | UNC (TPI) | UNF (TPI) | 8UN (TPI) | BSW (TPI) | BSF (TPI) |
|---|---|---|---|---|---|
| #0 (1/16) | - | 80 | - | 60 | - |
| #2 (3/32) | 56 | 64 | - | 48 | - |
| #4 (7/64) | 40 | 48 | - | 48 | - |
| #6 (9/64) | 32 | 40 | - | - | - |
| #8 (5/32) | 32 | 36 | - | 32 | - |
| #10 (3/16) | 24 | 32 | - | 24 | 32 |
| #12 (7/32) | 24 | 28 | - | 24 | 28 |
| 1/4 | 20 | 28 | - | 20 | 26 |
| 5/16 | 18 | 24 | - | 18 | 22 |
| 3/8 | 16 | 24 | - | 16 | 20 |
| 7/16 | 14 | 20 | - | 14 | 18 |
| 1/2 | 13 | 20 | - | 12 | 16 |
| 9/16 | 12 | 18 | - | 12 | 16 |
| 5/8 | 11 | 18 | - | 11 | 14 |
| 3/4 | 10 | 16 | - | 10 | 12 |
| 7/8 | 9 | 14 | - | 9 | 11 |
| 1 | 8 | 12 | 8 | 8 | 10 |
| 1-1/8 | 7 | 12 | 8 | 7 | 9 |
| 1-1/4 | 7 | 12 | 8 | 7 | 9 |
| 1-3/8 | 6 | 12 | 8 | 6 | 8 |
| 1-1/2 | 6 | 12 | 8 | 6 | 8 |
| 1-5/8 | 5.5 | 12 | 8 | - | 8 |
| 1-3/4 | 5 | 12 | 8 | 5 | 7 |
| 1-7/8 | 5 | 12 | 8 | 4.5 | - |
| 2 | 4.5 | 12 | 8 | 4.5 | 7 |
| 2-1/4 | 4.5 | 12 | 8 | - | - |
| 2-1/2 | 4 | 12 | 8 | - | - |
| 2-3/4 | 4 | 12 | 8 | - | - |
| 3 | 4 | 12 | 8 | - | - |
| 3-1/4 | 4 | - | 8 | - | - |
| 3-1/2 | 4 | - | 8 | - | - |
| 3-3/4 | 4 | - | 8 | - | - |
| 4 | 4 | - | 8 | - | - |