ASME B1.160° flank
Unified National Coarse Threads
The inch coarse series. Sizes below 1/4 in are designated by number (#4, #10) rather than by diameter, and those numbers are gauge numbers, not any fraction of an inch: #4 measures 0.112 in. 25 designations are listed here, all quoted in inches.
Dimensions25 sizes
| Designation | TPI | Major (in) | Pitch Ø (in) | Minor ext (in) | Tap drill (in) |
|---|---|---|---|---|---|
| #1-64 UNC | 64 | 0.073 | 0.063 | 0.0539 | 0.0574 |
| #2-56 UNC | 56 | 0.086 | 0.0744 | 0.0642 | 0.0681 |
| #3-48 UNC | 48 | 0.099 | 0.0854 | 0.0736 | 0.0781 |
| #4-40 UNC | 40 | 0.112 | 0.0957 | 0.0815 | 0.087 |
| #5-40 UNC | 40 | 0.125 | 0.1087 | 0.0945 | 0.1 |
| #6-32 UNC | 32 | 0.138 | 0.1177 | 0.0996 | 0.1067 |
| #8-32 UNC | 32 | 0.164 | 0.1437 | 0.1256 | 0.1328 |
| #10-24 UNC | 24 | 0.19 | 0.163 | 0.139 | 0.1483 |
| #12-24 UNC | 24 | 0.216 | 0.189 | 0.165 | 0.1743 |
| 1/4-20 UNC | 20 | 0.25 | 0.2177 | 0.1886 | 0.2 |
| 5/16-18 UNC | 18 | 0.3125 | 0.2764 | 0.2445 | 0.2569 |
| 3/8-16 UNC | 16 | 0.375 | 0.3343 | 0.2984 | 0.3125 |
| 7/16-14 UNC | 14 | 0.4375 | 0.3909 | 0.35 | 0.3661 |
| 1/2-13 UNC | 13 | 0.5 | 0.45 | 0.4055 | 0.4231 |
| 9/16-12 UNC | 12 | 0.5625 | 0.5083 | 0.4602 | 0.4792 |
| 5/8-11 UNC | 11 | 0.625 | 0.5661 | 0.5134 | 0.5341 |
| 3/4-10 UNC | 10 | 0.75 | 0.685 | 0.6272 | 0.65 |
| 7/8-9 UNC | 9 | 0.875 | 0.8028 | 0.7386 | 0.7639 |
| 1-8 UNC | 8 | 1 | 0.9189 | 0.8465 | 0.875 |
| 1-1/8-7 UNC | 7 | 1.125 | 1.0323 | 0.9496 | 0.9821 |
| 1-1/4-7 UNC | 7 | 1.25 | 1.1571 | 1.0748 | 1.1071 |
| 1-3/8-6 UNC | 6 | 1.375 | 1.2669 | 1.1705 | 1.2083 |
| 1-1/2-6 UNC | 6 | 1.5 | 1.3917 | 1.2957 | 1.3333 |
| 1-3/4-5 UNC | 5 | 1.75 | 1.6201 | 1.5047 | 1.55 |
| 2 UNC | 4.5 | 2 | 1.8555 | 1.7276 | 1.7778 |