Pipe Threads (BSP / NPT)
NPSL Straight Pipe Thread (Locknuts)
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
- 18
- Range
- 1/8" - 27 NPSL – 12" - 8 NPSL
| Nominal Diameter | Major Diameter mm | Major Diameter Inch | Tapping Drill Size mm | TPI | Pitch mm |
|---|---|---|---|---|---|
| 1/8" - 27 NPSL | 10,287 | 0,405 | 10,389 | 27 | 0,941 |
| 1/4" - 18 NPSL | 13,716 | 0,540 | 13,741 | 18 | 1,411 |
| 3/8" - 18 NPSL | 17,145 | 0,675 | 17,221 | 18 | 1,411 |
| 1/2" - 14 NPSL | 21,336 | 0,840 | 21,438 | 14 | 1,814 |
| 3/4" - 14 NPSL | 26,670 | 1,050 | 26,772 | 14 | 1,814 |
| 1" - 11 1/2 NPSL | 33,401 | 1,315 | 33,477 | 11,5 | 2,209 |
| 1 1/4" - 11 1/2 NPSL | 42,164 | 1,660 | 42,240 | 11,5 | 2,209 |
| 1 1/2" - 11 1/2 NPSL | 48,260 | 1,900 | 48,311 | 11,5 | 2,209 |
| 2" - 11 1/2 NPSL | 60,325 | 2,375 | 60,350 | 11,5 | 2,209 |
| 2 1/2" - 8 NPSL | 73,025 | 2,875 | 73,076 | 8 | 3,175 |
| 3" - 8 NPSL | 88,900 | 3,500 | 88,976 | 8 | 3,175 |
| 3 1/2" - 8 NPSL | 101,600 | 4,000 | 101,676 | 8 | 3,175 |
| 4" - 8 NPSL | 114,300 | 4,500 | 114,351 | 8 | 3,175 |
| 5" - 8 NPSL | 141,300 | 5,563 | 141,326 | 8 | 3,175 |
| 6" - 8 NPSL | 168,275 | 6,625 | 168,148 | 8 | 3,175 |
| 8" - 8 NPSL | 219,075 | 8,625 | 218,821 | 8 | 3,175 |
| 10" - 8 NPSL | 273,050 | 10,750 | 272,669 | 8 | 3,175 |
| 12" - 8 NPSL | 323,850 | 12,750 | 323,393 | 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.