Tapered thread is provided with a (Teflon) thread coating. BSPT is compliant with ISO 7.1 and is designated with an R. Use this thread on non-flat surfaces.
BSPP (G/parallel)
Parallel thread is provided with a counterbored O-ring seal. BSPP, compliant with ISO 228-A, is designated with a G. Use this thread when you have a flat surface.
M (metric)
Metric thread is provided with a counterbored O-ring or a metallic sealing ring. Metric thread, compliant with ISO R/262, is designated with an M.
N (NPT)
NPT thread is available on request and not stocked as standard. NPT thread is designated with an N.
U (universal short)
The tapered “Universal Short” thread has been designed to offer users the following advantages:
Reduced overall length
Smaller wrench size compared to parallel threads
Allows assembly with different female thread sizes
As a result, this thread can be used with BSPT, BSPP, and NPT threads.
