| Thread Designation BSPT | Nominal Size BSPT | Thread Form Type | Major Diameter mm d=D | Pitch mm p | Threads per inch tpi | Pitch Diameter mm d2=D2 | Minor Diameter Male Thd. d3=D3 | Thread Height H1 | Rounding r | Effective Thread Length mm External | Tap Drill Diameter mm |
|---|---|---|---|---|---|---|---|---|---|---|---|
| R 1/16 | 1/16" | BSPT | 7.723 | 0.907 | 28 | 7.142 | 6.561 | 0.581 | 0.125 | 2.5 | 6.4 |
| R 1/8 | 1/8" | BSPT | 9.728 | 0.907 | 28 | 9.147 | 8.566 | 0.581 | 0.125 | 2.5 | 8.4 |
| R 1/4 | 1/4" | BSPT | 13.157 | 1.337 | 19 | 12.301 | 11.445 | 0.856 | 0.184 | 3.7 | 11.2 |
| R 3/8 | 3/8" | BSPT | 16.662 | 1.337 | 19 | 15.806 | 14.95 | 0.856 | 0.184 | 3.7 | 14.75 |
| R 1/2 | 1/2" | BSPT | 20.955 | 1.814 | 14 | 19.793 | 18.631 | 1.162 | 0.249 | 5 | 18.25 |
| R 3/4 | 3/4" | BSPT | 26.441 | 1.814 | 14 | 25.279 | 24.117 | 1.162 | 0.249 | 5 | 23.75 |
| R 1 | 1" | BSPT | 33.249 | 2.309 | 11 | 31.77 | 30.291 | 1.479 | 0.317 | 6.4 | 30 |
| R 1 1/4 | 1 1/4" | BSPT | 41.91 | 2.309 | 11 | 40.431 | 38.952 | 1.479 | 0.317 | 6.4 | 38.5 |
| R 1 1/2 | 1 1/2" | BSPT | 47.803 | 2.309 | 11 | 46.324 | 44.845 | 1.479 | 0.317 | 6.4 | 44.5 |
| R 2 | 2" | BSPT | 59.614 | 2.309 | 11 | 58.135 | 56.656 | 1.479 | 0.317 | 7.5 | 56 |
| R 2 1/2 | 2 1/2" | BSPT | 75.184 | 2.309 | 11 | 73.705 | 72.226 | 1.479 | 0.317 | 9.2 | 71 |
| R 3 | 3" | BSPT | 87.884 | 2.309 | 11 | 86.405 | 84.926 | 1.479 | 0.317 | 9.2 | 85.5 |
| R 4 | 4" | BSPT | 113.03 | 2.309 | 11 | 111.551 | 110.072 | 1.479 | 0.317 | 10.4 | 110.5 |
| R 5 | 5" | BSPT | 138.43 | 2.309 | 11 | 136.951 | 135.472 | 1.479 | 0.317 | 11.5 | 136 |
| R 6 | 6" | BSPT | 163.83 | 2.309 | 11 | 162.351 | 160.872 | 1.479 | 0.317 | 11.5 | 161.5 |