1-1/2-11.5NPSH vs R1-1/4: 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 41.91 mm.
| Spec | 1-1/2-11.5NPSH | R1-1/4 |
|---|---|---|
| Designation | 1-1/2-11.5NPSH | R1-1/4 |
| Major diameter | 47.7 mm | 41.91 mm |
| Threads per inch / pitch | 11.5 | 11 |
| Thread form | straight (parallel), 60 degree | tapered, 55 degree |
| Seals on | gasket in the coupling | on the thread flanks with PTFE tape or paste |
Questions and answers
Which has the higher major diameter, 1-1/2-11.5NPSH or R1-1/4?
On major diameter, 1-1/2-11.5NPSH leads: 47.7 mm versus 41.91 mm.
How do 1-1/2-11.5NPSH and R1-1/4 compare?
On major diameter, 1-1/2-11.5NPSH leads: 47.7 mm versus 41.91 mm.