| PT, R, BSPT - 55° Taper Pipe Thread | ||||||||
| R1/8 | R1/4 | R3/8 | R1/2 | R3/4 | R1 | R1-1/4 | R1-1/2 | R2 |
| BSPP, G - 55° Parallel Pipe Thread | ||||||||
| G1/8 | G1/4 | G3/8 | G1/2 | G3/4 | G1 | G1-1/4 | G1-1/2 | G2 |
| UNF | NPT - 60° American Standard Taper Pipe Thread | ||||||||
| 10-32 UNF | 1/8 NPT | 1/4 NPT | 3/8 NPT | 1/2 NPT | 3/4 NPT | 1 NPT | 1-1/4 NPT | 1-1/2 NPT | 2 NPT |
| Metric Thread - 60° Parallel Thread | ||||||||||
| M5 x 0.8 | M6 x 1 | M8 x 1 | M8 x 1.25 | M10 x 1 | M10 x 1.25 | M12 x 1.25 | M12 x 1.5 | M14 x 1.5 | M16 x 1.5 | M20 x 1.5 |
BSP Thread
BSP thread form stands for British Standard Pipe and is most popular in the UK, Europe, Asia, Australia, New Zealand and South Africa.
There are two types of BSP threads:
- Parrallel (BSPP) - also known as G
- Tapered (BSPT) - also know as R or PT
Both threads have the same pitch, angle (55 degrees) and shape (rounded peaks and valleys).
NPT Thread
NPT stands for National Pipe Thread and is an American standard thread. It may also be reffered to as MPT, MNPT or NPT (M) for male external threads and FPT, FNPT or NPT(F) for female internal threads. A thread sealant must always be used to achieve a leak free seal (except for NPTF). It is also based on Trade Size rather than actual diameter (similar to BSP in this regard).
Both threads have the same pitch, angle (60 degrees) and shape (flat peaks and valleys).