British Standard Pipe Tapered (BSPT)
Sealing – Sealing is accomplished by distorting the threads. Thread sealant tape is recommended for a leak free connection. A properly chamfered BSPT male will seal with a BSPP Female Swivel.
| Inch Size | Dash Size | Nominal Thread | Male Thread OD (inch) | Female Thread ID (inch) |
| 1/8 | -02 | R1/8×28 | 3/8 (0.38) | 11/32 (0.35) |
| 1/4 | -04 | R1/4×19 | 33/64 (0.52) | 15/32 (0.47) |
| 3/8 | -06 | R3/8×19 | 21/32 (0.65) | 19/32 (0.60) |
| 1/2 | -08 | R1/2×14 | 13/16 (0.82) | 3/4 (0.75) |
| 5/8 | -10 | R5/8×14 | 7/8 (0.88) | 13/16 (0.80) |
| 3/4 | -12 | R3/4×14 | 1-1/32 (1.04) | 31/32 (0.97) |
| 1 | -16 | R1x11 | 1-5/16 (1.30) | 1-7/32 (1.22) |
| 1-1/4 | -20 | R1-1/4×11 | 1-21/32 (1.65) | 1-9/16 (1.56) |
| 1-1/2 | -24 | R1-1/2×11 | 1-7/8 (1.88) | 1-25/32 (1.79) |
| 2 | -32 | R2x11 | 2-11/32 (2.35) | 2-1/4 (2.26) |
