British Standard Pipe - BSP
BSP = British Standard Pipe, or BSPP = British Standard Parallel Pipe, or BSPF = British Standard Parallel Fixed.
This thread needs a gasket or seal to be gas/liquid tight.
BSP (British Standard Pipe) Thread Data
Angle of thread = 55°
| Nominal Size (inches) | T P I | Pitch (inches) | Major Diameter (inches) | Minor Diameter (inches) | Tapping Drill Size |
|---|---|---|---|---|---|
| 1/16 | 28 | 0.0357 | 0.304 | 0.2583 | Letter drill G (6.6 mm) |
| 1/8 | 28 | 0.0357 | 0.383 | 0.3372 | 11/32 inch (8.73 mm) |
| 1/4 | 19 | 0.0526 | 0.518 | 0.4546 | 11.8 mm (0.4646 inch) |
| 3/8 | 19 | 0.0526 | 0.656 | 0.5886 | 15.25 mm (0.6004 inch) |
| 1/2 | 14 | 0.0714 | 0.825 | 0.7336 | 3/4 inch (19.05 mm) |
| 5/8 | 14 | 0.0714 | 0.902 | 0.8106 | 21 mm (0.8268 inch) |
| 3/4 | 14 | 0.0714 | 1.041 | 0.9496 | 24.5 mm (0.9646 inch) |
| 7/8 | 14 | 0.0714 | 1.189 | 1.0976 | 28.25 mm (1.1122 inch) |
| 1 inch | 11 | 0.0909 | 1.309 | 1.1926 | 30.75 mm (1.2106 inch) |