by Support Support
- Last updated Jan 11, 2022
- Livestock, Metal Valves
BSPP Thread Standards
BSPP aka British Standard Pipe Parallel threads are also sometimes abbreviated as BSP threads. The standards of male BSP thread [designated as G] are governed by ISO 228 while the standards of female BSP threads [designated as Rp ] are governed by ISO 7 standards. The fig.1 below illustrates the nomenclature related to the thread where the thread angle is 55 degrees.
Fig. 1: The BSPP Thread Nomenclature
BSPP Male Thread Standards (G)
Size | D (mm) | D1 (mm) | D2 (mm) | h (mm) | P (mm) | TPI |
1/16" | 7.723 | 6.561 | 7.142 | 0.581 | 0.907 | 28 |
1/8" | 9.728 | 8.566 | 9.147 | 0.581 | 0.907 | 28 |
1/4" | 13.157 | 11.445 | 12.301 | 0.856 | 1.337 | 19 |
3/8" | 16.662 | 14.95 | 15.806 | 0.856 | 1.3358 | 19 |
1/2" | 20.955 | 18.631 | 19.793 | 1.162 | 1.8143 | 14 |
3/4" | 26.441 | 24.117 | 25.279 | 1.162 | 1.8143 | 14 |
1" | 33.249 | 30.291 | 31.770 | 1.479 | 2.3091 | 11 |
1 1/4" | 41.910 | 38.952 | 40.431 | 1.479 | 2.3091 | 11 |
1 1/2" | 47.803 | 44.845 | 46.324 | 1.479 | 2.3091 | 11 |
2" | 59.614 | 56.656 | 58.135 | 1.479 | 2.3091 | 11 |
2 1/2" | 75.184 | 72.226 | 73.705 | 1.479 | 2.3091 | 11 |
3" | 87.884 | 84.926 | 86.405 | 1.479 | 2.3091 | 11 |
4" | 113.03 | 110.07 | 111.55 | 1.479 | 2.3091 | 11 |
5" | 138.43 | 135.47 | 136.95 | 1.479 | 2.3091 | 11 |
6" | 163.83 | 160.87 | 162.35 | 1.479 | 2.3091 | 11 |
BSPP Female Thread Standards (Rp)
Size | D2 or Hole Size (mm) |
1/16" | 6.84 |
1/8" | 8.85 |
1/4" | 11.89 |
3/8" | 15.40 |
1/2" | 19.17 |
3/4" | 24.66 |
1" | 30.93 |
1 1/4" | 39.59 |
1 1/2" | 45.49 |
2" | 57.30 |
2 1/2" | 72.87 |
3" | 85.57 |
4" | 110.71 |
5" | 136.11 |
6" | 161.51 |
Thread Compatibility
Thread Profile | Matching Profile | Seal Type |
BSPP Female Thread (Rp) | BSPP Male Thread (G) | O - ring or washer |
BSPP Female Thread (Rp) | BSPT Male Thread (R) | Tape or Pipe dope |