1-1/2-9NH vs 1-1/2-11.5NPSH: specs compared

Updated 05 September 2026.

50.55 mm
1-1/2-9NH wins on major diameter

On major diameter, 1-1/2-9NH leads: 50.55 mm versus 47.7 mm.

Spec1-1/2-9NH1-1/2-11.5NPSH
Designation1-1/2-9NH1-1/2-11.5NPSH
Major diameter50.55 mm47.7 mm
Threads per inch / pitch911.5
Thread formstraight (parallel), 60 degreestraight (parallel), 60 degree
Seals onrubber gasket in the female swivelgasket in the coupling

Questions and answers

Which has the higher major diameter, 1-1/2-9NH or 1-1/2-11.5NPSH?

On major diameter, 1-1/2-9NH leads: 50.55 mm versus 47.7 mm.

How do 1-1/2-9NH and 1-1/2-11.5NPSH compare?

On major diameter, 1-1/2-9NH leads: 50.55 mm versus 47.7 mm.

Compared here

1-1/2" NH fire hose thread (NST) (1-1/2-9NH)1-1/2" NPSH straight hose thread (1-1/2-11.5NPSH)