Fire Hose Thread Chart
The following is a listing of the most commonly used threads.
| National Standard | Straight from Pipe | |||
| NH* | NPSH | |||
| Size | ODM | TPI | ODM | TPI |
| 3/4 | 1.375 | 8 | 1.035 | 14* |
| 1 | 1.375 | 8 | 1.295 | 11 1/2* |
| 1 1/4 | 1.671 | 9 | 1.639 | 11 1/2* |
| 1 1/2 | 1.990 | 9 | 1.878 | 11 1/2* |
| 2 | 2.515 | 8 | 2.353 | 11 1/2* |
| 2 1/2 | 3.068 | 7 1/2 | 2.855 | 8* |
| 3 | 3.623 | 6 | 3.470 | 8 |
| 3 1/2 | 4.243 | 6 | 3.970 | 8 |
| 4 | 5.010 | 4 | 4.470 | 8 |
| 4 1/2 | 5.760 | 4 | 4.970 | 8 |
| 5 | 6.260 | 4 | -- | -- |
| 6 | 7.025 | 4 | -- | -- |
| *National Form Thread | ||||
| Note: NPT (Tapered Pipe) not available on female swivels. | ||||