JG4 vs MFL: specs compared
Updated 05 September 2026.
6
specs differ
JG4 and MFL differ on 6 specs: designation, size / thread, fitting form, seals on, rating / role, tube od.
| Spec | JG4 | MFL |
|---|---|---|
| Designation | 4 mm OD | 1/4" MFL (7/16"-20 UNF) |
| Size / thread | 4 mm OD tube | 7/16"-20 UNF male thread, 45 degree flare seat |
| Fitting form | push-fit collet, metric | SAE 45 degree flare, male |
| Seals on | single O-ring plus a stainless collet grab-ring | metal 45 degree flare face, never PTFE tape |
| Rating / role | John Guest Speedfit metric fittings for 4mm OD tube; tube OD must be within 0.1mm of nominal | the homebrew flare standard on regulators, manifolds and disconnect tails |
| Tube OD | 4 mm |
Questions and answers
How do JG4 and MFL compare?
JG4 and MFL differ on 6 specs: designation, size / thread, fitting form, seals on, rating / role, tube od.