Jg38 vs JG8: specs compared
Updated 05 September 2026.
9.53 mm
Jg38 wins on tube outer diameter
On tube outer diameter, Jg38 leads: 9.53 mm versus 7.94 mm.
| Spec | Jg38 | JG8 |
|---|---|---|
| Designation | 3/8" (9.5 mm) OD | 5/16" (8 mm) OD |
| Size / thread | 3/8" (9.53 mm) | 5/16" (about 7.94 mm) |
| Fitting form | push-fit collet, imperial | push-fit collet, imperial |
| Seals on | single O-ring plus stainless collet grab-ring | single O-ring plus stainless collet grab-ring |
| Rating / role | Speedfit acetal fittings rated to 12 bar at 20 C, 6 bar at 65 C | John Guest Speedfit rated 16 bar at 1 C, 10 bar at 20 C |
| Tube OD | 9.53 mm | 7.94 mm |
Questions and answers
Which has the higher tube outer diameter, Jg38 or JG8?
On tube outer diameter, Jg38 leads: 9.53 mm versus 7.94 mm.
How do Jg38 and JG8 compare?
On tube outer diameter, Jg38 leads: 9.53 mm versus 7.94 mm.