British Standard Pipe Thread Nipples(BSPT Nipples) is a family of standard screw thread types that has been adopted internationally for interconnecting and sealing pipe ends by mating an external male with an internal female thread.

Two types of British Standard Pipe Thread Nipples (BSPT Nipples) are distinguished by a Parallel or straight threads, British Standard Pipe Parallel thread which have a constant diameter that is noted by the letter G. British Standard Pipe Taper thread (BSPT), or taper threads diameters decreases or increases by the length of the thread that is noted by the letter R.

British Standard Pipe Thread Nipples (BSPT Nipples) can be combined into two types of joints. A jointing threads thas is pipe threads where pressure tightness is made through the mating of two threads together. They always use a taper male thread, but can have either parallel or taper female threads. A longscrew threads that are parallel pipe threads used where a pressure tight joint is achieved by the compression of a soft material such as a washer or o-ring seal between the end face of the male thread and a socket or nipple face, with tightening of a backnut.