1/4-18 NPT vs 2-11.5NPSH: specs compared
Updated 05 September 2026.
59.74 mm
2-11.5NPSH wins on major diameter
On major diameter, 2-11.5NPSH leads: 59.74 mm versus 13.72 mm.
| Spec | 1/4-18 NPT | 2-11.5NPSH |
|---|---|---|
| Designation | 1/4-18 NPT | 2-11.5NPSH |
| Major diameter | 13.72 mm | 59.74 mm |
| Threads per inch / pitch | 18 | 11.5 |
| Thread form | tapered, 60 degree | straight (parallel), 60 degree |
| Seals on | on the thread flanks with PTFE tape | gasket in the coupling |
Questions and answers
Which has the higher major diameter, 1/4-18 NPT or 2-11.5NPSH?
On major diameter, 2-11.5NPSH leads: 59.74 mm versus 13.72 mm.
How do 1/4-18 NPT and 2-11.5NPSH compare?
On major diameter, 2-11.5NPSH leads: 59.74 mm versus 13.72 mm.