by Support Support
- Last updated Jan 12, 2022
- Livestock, Metal Valves
BSPT Thread Standards
British Standard Pipe Taper aka BSPT threads are governed by ISO 7 standards. The male threads are usually designated as "R" while the female threads are usually designated as "Rc". The fig.1 below illustrates the nomenclature related to the thread where the thread angle is 55 degrees.
Fig. 1: The BSPT Thread Nomenclature
BSPT Male Thread Standards (R)
Size | D (mm) | D1 (mm) | D2 (mm) | h (mm) | P (mm) | TPI | Min. Gauge |
1/16" | 7.723 | 6.561 | 7.142 | 0.581 | 0.907 | 28 | 5.6 |
1/8" | 9.728 | 8.566 | 9.147 | 0.581 | 0.907 | 28 | 5.6 |
1/4" | 13.157 | 11.445 | 12.301 | 0.856 | 1.337 | 19 | 8.4 |
3/8" | 16.662 | 14.950 | 15.806 | 0.856 | 1.337 | 19 | 8.8 |
1/2" | 20.955 | 18.631 | 19.793 | 1.162 | 1.814 | 14 | 11.4 |
3/4" | 26.441 | 24.117 | 25.279 | 1.162 | 1.814 | 14 | 12.7 |
1" | 33.249 | 30.291 | 31.770 | 1.479 | 2.309 | 11 | 14.5 |
1 1/4" | 41.910 | 38.952 | 40.431 | 1.479 | 2.309 | 11 | 16.8 |
1 1/2" | 47.803 | 44.845 | 46.324 | 1.479 | 2.309 | 11 | 16.8 |
2" | 59.614 | 56.656 | 58.135 | 1.479 | 2.309 | 11 | 21.1 |
2 1/2" | 75.184 | 72.226 | 73.705 | 1.479 | 2.309 | 11 | 23.2 |
3" | 87.884 | 84.926 | 86.405 | 1.479 | 2.309 | 11 | 26.3 |
4" | 113.03 | 110.07 | 111.55 | 1.479 | 2.309 | 11 | 32.3 |
5" | 138.43 | 135.47 | 136.95 | 1.479 | 2.309 | 11 | 36.6 |
6" | 163.83 | 160.87 | 162.35 | 1.479 | 2.309 | 11 | 36.6 |
BSPT Thread Standards (Rc)
Size | D2 or Hole Size (mm) |
1/16" | 6.470 |
1/8" | 8.495 |
1/4" | 11.340 |
3/8" | 14.846 |
1/2" | 18.489 |
3/4" | 23.975 |
1" | 30.110 |
1 1/4" | 38.802 |
1 1/2" | 44.665 |
2" | 56.476 |
2 1/2" | 72.010 |
3" | 84.710 |
Thread Compatibility
Thread Profile | Matching Profile | Seal Type |
BSPT Female Thread (Rc) | BSPT Male Thread (R) | Tape or Pipe dope |