BSP British Standard Pipe
BS thread - 55° profile
| Size | TPI | Pitch in | Ext Major in | Int Minor in | Tap Drill Size in | Tap Drill Size mm |
|---|---|---|---|---|---|---|
| 1/16" | 28 | 0.0357 | 0.3041 | 0.2583 | G | 6.8 |
| 1/8" | 28 | 0.0357 | 0.3830 | 0.3373 | 11/32" | 8.8 |
| 1/4" | 19 | 0.0526 | 0.5180 | 0.4506 | 29/64" | 11.8 |
| 3/8" | 19 | 0.0526 | 0.6560 | 0.5886 | 19/32" | 15.3 |
| 1/2" | 14 | 0.0714 | 0.8250 | 0.7336 | 3/4" | 19.1 |
| 5/8" | 14 | 0.0714 | 0.9020 | 0.8106 | 53/64" | 21.1 |
| 3/4" | 14 | 0.0714 | 1.0410 | 0.9496 | 31/32" | 24.6 |
| 7/8" | 14 | 0.0714 | 1.1890 | 1.0976 | 1 7/64" | 28.3 |
| 1" | 11 | 0.0909 | 1.3090 | 1.1926 | 1 13/64" | 30.9 |
| 1.25" | 11 | 0.0909 | 1.6500 | 1.5336 | 1 35/64" | 39.5 |
| 1.5" | 11 | 0.0909 | 1.8820 | 1.7656 | 1-25/32" | 45.4 |
| 1.75" | 11 | 0.0909 | 2.1160 | 1.9996 | 2" | 51.4 |
| 2" | 11 | 0.0909 | 2.3470 | 2.2306 | 2-1/4" | 57.2 |
| 2.25" | 11 | 0.0909 | 2.5870 | 2.4706 | 2 5/32" | 63.3 |
| 2.5" | 11 | 0.0909 | 2.9600 | 2.8436 | 2 27/32" | 72.8 |
| 2.75" | 11 | 0.0909 | 3.2100 | 3.0936 | 3 3/32" | 79.2 |
| 3" | 11 | 0.0909 | 3.4600 | 3.3436 | 3 11/32" | 85.5 |
| 3.5" | 11 | 0.0909 | 3.9500 | 3.8336 | 3 53/64" | 98.0 |
| 4" | 11 | 0.0909 | 4.4500 | 4.3336 | 4 21/64" | 110.7 |
| 5" | 11 | 0.0909 | 5.4500 | 5.3336 | 5 21/64" | 136.1 |
| 6" | 11 | 0.0909 | 6.4500 | 6.3336 | 6 21/64" | 161.5 |