BSPP (G) Parallel Pipe Threads Chart
| BASIC DIMENSIONS AND PITCH | ||||
|---|---|---|---|---|
| BSPP designation | Nominal pipe size | TPI | Pitch (mm) | Form |
| G 1/8 | 1/8 | 28 | 0.907 | 55° Whitworth |
| G 1/4 | 1/4 | 19 | 1.337 | 55° Whitworth |
| G 3/8 | 3/8 | 19 | 1.337 | 55° Whitworth |
| G 1/2 | 1/2 | 14 | 1.814 | 55° Whitworth |
| G 3/4 | 3/4 | 14 | 1.814 | 55° Whitworth |
| G 1 | 1 | 11 | 2.309 | 55° Whitworth |
| G 1 1/4 | 1 1/4 | 11 | 2.309 | 55° Whitworth |
| G 1 1/2 | 1 1/2 | 11 | 2.309 | 55° Whitworth |
| G 2 | 2 | 11 | 2.309 | 55° Whitworth |
| G 2 1/2 | 2 1/2 | 11 | 2.309 | 55° Whitworth |
| G 3 | 3 | 11 | 2.309 | 55° Whitworth |
| G 4 | 4 | 11 | 2.309 | 55° Whitworth |
G threads are parallel. Nominal pipe size is not the thread outside diameter. Pitch values are converted from the listed TPI; diameter and tolerance limits belong to ISO 228-1.