Both NPT and BSP are pipe thread standards for screw threads used on pipes and pipe fittings to seal pipes.
- NPT threads have a 60° angle and have flattened peaks and valleys.
- BSP threads have a 55° angle and have rounded peaks and valleys (Whitworth thread form)
- BSP is British Standard Pipe technical standards, it is divided into two types as follows:
-- BSPT (British Standard Pipe Taper), aka G or Rp
-- BSPP (British Standard Pipe Parallel), aka R or Rc
ISO 228: for joint of external and internal parallel threads (G)/ BSPP.
ISO 7 or EN 10226: for external taper (R), internal parallel (Rp) and internal taper (Rc) BSPT.
- NPT is American Standard Taper Pipe Thread (ANSI/ASME B1.20.1), Taper 1:16.
BSPP is totally different from both BSPT and NPT, as it parallel threads.
BSP thread dimensions as follows:
NPT thread dimensions as follows:
