parallel (BSPP) and tapered (BSPT)

Great Britain BSPP (British Standard Pipe Parallel)
Bsp fitting is the most popular metric pipe thread end in Great Britain. These threads are either parallel (BSPP) or tapered (BSPT). The male BSPP will mate with a BSPP (parallel female or a female port). The male BSPT will mate with the BSPP female swivel. The male has straight threads and a 30-degree inverted seat. The BSPP female has straight threads and a 30-degree inverted seat. The female port has straight threads and spotface. The seal on the port is made with an "O" Ring or a soft metal washer on the male. The BSPP connector is similar to, but not interchangeable with our FPX. The thread pitch is different in most sizes, and the thread angle is 55-degrees instead of the 60-degree angle found on NPSM threads.
BSPT (British Standard Pipe Tapered)
The BSPT male will mate with a BSPT female and the BSPP female swivel. The BSPT male has tapered threads and a 30-degree inverted seat. The BSPT connector is similar to but not interchangeable with our MP. The thread pitch is different in most cases, and the thread angle is 55 degrees instead of the 60-degree angle found on NPTF threads. Neither the British parallel hydraulic hose or the British tapered pipe has true metric threads, although many people find these threads "foreign" and conclude they must be "metric."