Standard British Standard Pipe Parallel (BSPP)
Popular couplings British Standard Pipe (BSP) threads, also known as Whitworth threads.
The BSPP (parallel) male will mate with a BSPP (parallel) female or a female port. The BSPP male has straight threads and a 30° seat. The BSPP female has straight threads and a 30° seat.
The female swivel BSPP has a tapered nose which seals on the cone seat of the male.
The BSPP (parallel) connector is similar to, but not interchangeable with, the NPSM connector. The thread pitch is different in most sizes, and the thread angle is 55° instead of the 60° angle found on NPSM threads.