1-11.5 NPT vs 1-1/2-11.5 NPT: specs compared
Updated 05 September 2026.
48.26 mm
1-1/2-11.5 NPT wins on major diameter
On major diameter, 1-1/2-11.5 NPT leads: 48.26 mm versus 33.4 mm.
| Spec | 1-11.5 NPT | 1-1/2-11.5 NPT |
|---|---|---|
| Designation | 1-11.5 NPT | 1-1/2-11.5 NPT |
| Major diameter | 33.4 mm | 48.26 mm |
| Threads per inch / pitch | 11.5 | 11.5 |
| Thread form | tapered, 60 degree | tapered, 60 degree |
| Seals on | on the thread flanks with PTFE tape | on the thread flanks with PTFE tape |
Questions and answers
Which has the higher major diameter, 1-11.5 NPT or 1-1/2-11.5 NPT?
On major diameter, 1-1/2-11.5 NPT leads: 48.26 mm versus 33.4 mm.
How do 1-11.5 NPT and 1-1/2-11.5 NPT compare?
On major diameter, 1-1/2-11.5 NPT leads: 48.26 mm versus 33.4 mm.