Standard diametral pitch (Pd) values for inch-system gears. Diametral pitch is the number of teeth per inch of pitch diameter. Fine pitch (higher Pd) and coarse pitch (lower Pd) are shown separately.
| Name | Pd |
|---|---|
| 20 | 20 |
| 22 | 22 |
| 24 | 24 |
| 28 | 28 |
| 32 | 32 |
| 36 | 36 |
| 38 | 38 |
| 40 | 40 |
| 44 | 44 |
| 48 | 48 |
| 52 | 52 |
| 56 | 56 |
| 60 | 60 |
| 64 | 64 |
| 72 | 72 |
| Name | Pd |
|---|---|
| 3/4 | 0.75 |
| 7/8 | 0.875 |
| 1 | 1 |
| 1 1/4 | 1.25 |
| 1 1/2 | 1.5 |
| 1 3/4 | 1.75 |
| 2 | 2 |
| 2 1/4 | 2.25 |
| 2 1/2 | 2.5 |
| 2 3/4 | 2.75 |
| 3 | 3 |
| 3 1/2 | 3.5 |
| 4 | 4 |
| 4 1/2 | 4.5 |
| 5 | 5 |
| 5 1/2 | 5.5 |
| 6 | 6 |
| 7 | 7 |
| 8 | 8 |
| 9 | 9 |
| 10 | 10 |
| 11 | 11 |
| 12 | 12 |
| 13 | 13 |
| 14 | 14 |
| 16 | 16 |
| 18 | 18 |