The two most popular thread styles in the world are British Standard Pipe (BSP) and
National Pipe Taper (NPT). They are the international standard for joining fittings and pipes.
BSP threads
BSP is the abbreviation for British Standard Pipe. The thread, as defined by the ISO 228 standard, uses Whitworth standard threads, and is among a number of technical standards for screw threads that has been adopted internationally for interconnecting and sealing pipes and fittings. It has been adopted as standard in plumbing and pipe fitting nearly worldwide.
NPT threads
NPT stands for National Pipe Thread and is an American standard thread. It may also be referred 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).
The difference
BSP and NPT threads have more to do with where than what, which is an important distinction. Where NPT is prevalent in the U.S. and Canada, BSP is the primary standard in the UK, Europe, Asia, Australia, New Zealand, South Africa and many other countries.
NPT and BSP threads are not interchangeable due to the differences in thread forms. NPT threads are pointed in the peaks and valleys, where BSPs are rounded. Most notably, the NPT thread angle is 60 degrees versus the BSP 55-degree angle.
QC Hydraulics has a wide range of stainless steel BSP fittings and stainless steel NPT fittings that is sure to suit your needs, please contact our sales team for more details.