NPTF Dryseal Pipe Threads Chart
| BASIC DIMENSIONS AND PITCH | ||||
|---|---|---|---|---|
| Nominal pipe size (in) | Pipe outside diameter (in) | TPI | Pitch (in) | Profile |
| 1/16 | 0.3125 | 27 | 0.03704 | NPTF / NPSI |
| 1/8 | 0.4050 | 27 | 0.03704 | NPTF / NPSF |
| 1/4 | 0.5400 | 18 | 0.05556 | NPTF / NPSF |
| 3/8 | 0.6750 | 18 | 0.05556 | NPTF / NPSF |
| 1/2 | 0.8400 | 14 | 0.07143 | NPTF / NPSF |
| 3/4 | 1.0500 | 14 | 0.07143 | NPTF / NPSF |
| 1 | 1.3150 | 11.5 | 0.08696 | NPTF / NPSF |
| 1 1/4 | 1.6600 | 11.5 | 0.08696 | NPTF / NPSF |
| 1 1/2 | 1.9000 | 11.5 | 0.08696 | NPTF / NPSF |
| 2 | 2.3750 | 11.5 | 0.08696 | NPTF / NPSF |
| 2 1/2 | 2.8750 | 8 | 0.12500 | NPTF |
| 3 | 3.5000 | 8 | 0.12500 | NPTF |
| 4 | 4.5000 | 8 | 0.12500 | NPTF |
Nominal size, pipe OD and pitch follow the corresponding NPT size series. Dryseal crest/root truncations, gaging lengths and limits are controlled by ASME B1.20.3 and B1.20.5.