R1 vs 1-11.5NPSH: specs compared
Updated 05 September 2026.
33.249 mm
R1 wins on major diameter
On major diameter, R1 leads: 33.249 mm versus 32.89 mm.
| Spec | R1 | 1-11.5NPSH |
|---|---|---|
| Designation | R1 | 1-11.5NPSH |
| Major diameter | 33.249 mm | 32.89 mm |
| Threads per inch / pitch | 11 | 11.5 |
| Thread form | tapered, 55 degree | straight (parallel), 60 degree |
| Seals on | on the thread flanks with PTFE tape or paste | gasket in the coupling |
Questions and answers
Which has the higher major diameter, R1 or 1-11.5NPSH?
On major diameter, R1 leads: 33.249 mm versus 32.89 mm.
How do R1 and 1-11.5NPSH compare?
On major diameter, R1 leads: 33.249 mm versus 32.89 mm.