G1-1/2 vs 1-1/2-11.5NPSH: specs compared

Updated 05 September 2026.

47.803 mm
G1-1/2 wins on major diameter

On major diameter, G1-1/2 leads: 47.803 mm versus 47.7 mm.

SpecG1-1/21-1/2-11.5NPSH
DesignationG1-1/21-1/2-11.5NPSH
Major diameter47.803 mm47.7 mm
Threads per inch / pitch1111.5
Thread formparallel, 55 degreestraight (parallel), 60 degree
Seals onflat washer or bonded seal on the facegasket in the coupling

Questions and answers

Which has the higher major diameter, G1-1/2 or 1-1/2-11.5NPSH?

On major diameter, G1-1/2 leads: 47.803 mm versus 47.7 mm.

How do G1-1/2 and 1-1/2-11.5NPSH compare?

On major diameter, G1-1/2 leads: 47.803 mm versus 47.7 mm.

Compared here

1-1/2" BSP parallel (G1-1/2 / BSPP) (G1-1/2)1-1/2" NPSH straight hose thread (1-1/2-11.5NPSH)