R1/2 vs R1/8: specs compared
Updated 05 September 2026.
20.955 mm
R1/2 wins on major diameter
On major diameter, R1/2 leads: 20.955 mm versus 9.728 mm.
| Spec | R1/2 | R1/8 |
|---|---|---|
| Designation | R1/2 | R1/8 |
| Major diameter | 20.955 mm | 9.728 mm |
| Threads per inch / pitch | 14 | 28 |
| Thread form | tapered, 55 degree | tapered, 55 degree |
| Seals on | on the thread flanks with PTFE tape or paste | on the thread flanks with PTFE tape or paste |
Questions and answers
Which has the higher major diameter, R1/2 or R1/8?
On major diameter, R1/2 leads: 20.955 mm versus 9.728 mm.
How do R1/2 and R1/8 compare?
On major diameter, R1/2 leads: 20.955 mm versus 9.728 mm.