G3/8 vs R3/8: specs compared
Updated 05 September 2026.
3
specs differ
G3/8 and R3/8 differ on 3 specs: designation, thread form, seals on.
| Spec | G3/8 | R3/8 |
|---|---|---|
| Designation | G3/8 | R3/8 |
| Major diameter | 16.662 mm | 16.662 mm |
| Threads per inch / pitch | 19 | 19 |
| Thread form | parallel, 55 degree | tapered, 55 degree |
| Seals on | flat washer or bonded seal on the face | on the thread flanks with PTFE tape or paste |
Questions and answers
How do G3/8 and R3/8 compare?
G3/8 and R3/8 differ on 3 specs: designation, thread form, seals on.