BSP      British Standard Pipe
BSPT    British Standard Pipe Taper
NPT      National Pipe Taper
 

CLASSIFICATION COUPLING TYPE STANDARD THREAD TYPICAL CALL OUT SEALING METHOD
FEMALE THREADED A/D ISO 228-1
JIS B0202
BSP G Parallel thread
ISO 7/1
JIS B0203
BSPT RC Conical thread
ANSI B1.20.1 NPT N Conical thread
MALE THREADED B/F ISO 7/1
JIS B0203
BSPT R Conical thread
ANSI B1.20.1 NPT N Conical thread