Acme Threads Chart
| BASIC DIMENSIONS AND PITCH | ||||
|---|---|---|---|---|
| Nominal size (in) | TPI | Basic major D (in) | Basic pitch E (in) | Basic minor K (in) |
| 1/4 | 16 | 0.2500 | 0.2188 | 0.1875 |
| 5/16 | 14 | 0.3125 | 0.2768 | 0.2411 |
| 3/8 | 12 | 0.3750 | 0.3333 | 0.2917 |
| 7/16 | 12 | 0.4375 | 0.3958 | 0.3542 |
| 1/2 | 10 | 0.5000 | 0.4500 | 0.4000 |
| 5/8 | 8 | 0.6250 | 0.5625 | 0.5000 |
| 3/4 | 6 | 0.7500 | 0.6667 | 0.5833 |
| 7/8 | 6 | 0.8750 | 0.7917 | 0.7083 |
| 1 | 5 | 1.0000 | 0.9000 | 0.8000 |
| 1 1/4 | 5 | 1.2500 | 1.1500 | 1.0500 |
| 1 1/2 | 4 | 1.5000 | 1.3750 | 1.2500 |
| 2 | 4 | 2.0000 | 1.8750 | 1.7500 |
| 2 1/2 | 3 | 2.5000 | 2.3333 | 2.1667 |
| 3 | 2 | 3.0000 | 2.7500 | 2.5000 |
| 4 | 2 | 4.0000 | 3.7500 | 3.5000 |
| 5 | 2 | 5.0000 | 4.7500 | 4.5000 |
General-purpose Acme basic dimensions are shown. Centralizing series and tolerance classes use additional diameter allowances; the current ASME B1.5 standard controls those limits.