Pipe Threads (BSP / NPT)
NPSC Straight Pipe Thread (Couplings)
Pipe threads seal or connect pipework. Tapered forms (NPT, BSPT/R) seal on the thread itself; parallel forms (BSPP/G, NPS) seal with a gasket or O-ring.
- Standard
- ANSI B1.20.1
- Flank angle
- 60°
- Sizes listed
- 13
- Range
- 1/8" - 27 NPSC – 4" - 8 NPSC
| Nominal Diameter | Major Diameter mm | Major Diameter Inch | Tapping Drill Size mm | TPI | Pitch mm |
|---|---|---|---|---|---|
| 1/8" - 27 NPSC | 10.034 | 0.395 | 8.636 | 27 | 0.941 |
| 1/4" - 18 NPSC | 13.329 | 0.525 | 11.227 | 18 | 1.411 |
| 3/8" - 18 NPSC | 16.768 | 0.660 | 14.656 | 18 | 1.411 |
| 1/2" - 14 NPSC | 20.888 | 0.822 | 18.161 | 14 | 1.814 |
| 3/4" - 14 NPSC | 26.235 | 1.033 | 23.495 | 14 | 1.814 |
| 1" - 11 1/2 NPSC | 32.848 | 1.293 | 29.489 | 11.5 | 2.209 |
| 1 1/4" - 11 1/2 NPSC | 41.603 | 1.638 | 38.252 | 11.5 | 2.209 |
| 1 1/2" - 11 1/2 NPSC | 47.674 | 1.877 | 44.323 | 11.5 | 2.209 |
| 2" - 11 1/2 NPSC | 59.711 | 2.351 | 56.363 | 11.5 | 2.209 |
| 2 1/2" - 8 NPSC | 72.214 | 2.843 | 67.310 | 8 | 3.175 |
| 3" - 8 NPSC | 88.125 | 3.469 | 83.236 | 8 | 3.175 |
| 3 1/2" - 8 NPSC | 100.832 | 4.970 | 95.936 | 8 | 3.175 |
| 4" - 8 NPSC | 113.489 | 4.468 | 108.585 | 8 | 3.175 |
Reference values only. Verify against the current edition of the governing standard before use in production drawings or manufacturing. Provided by Micro Components as a free engineering resource.