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

Updated 05 September 2026.

47.7 mm
1-1/2-11.5NPSH wins on major diameter

On major diameter, 1-1/2-11.5NPSH leads: 47.7 mm versus 33.4 mm.

Spec1-11.5 NPT1-1/2-11.5NPSH
Designation1-11.5 NPT1-1/2-11.5NPSH
Major diameter33.4 mm47.7 mm
Threads per inch / pitch11.511.5
Thread formtapered, 60 degreestraight (parallel), 60 degree
Seals onon the thread flanks with PTFE tapegasket in the coupling

Questions and answers

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

On major diameter, 1-1/2-11.5NPSH leads: 47.7 mm versus 33.4 mm.

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

On major diameter, 1-1/2-11.5NPSH leads: 47.7 mm versus 33.4 mm.

Compared here

1" NPT (National Pipe Taper) (1-11.5 NPT)1-1/2" NPSH straight hose thread (1-1/2-11.5NPSH)