FFL vs G5/8 regulator inlet (G5/8 (BSP parallel)): specs compared
Updated 05 September 2026.
5
specs differ
FFL and G5/8 regulator inlet (G5/8 (BSP parallel)) differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | FFL | G5/8 regulator inlet (G5/8 (BSP parallel)) |
|---|---|---|
| Designation | 1/4" FFL (7/16"-20 UNF) | G5/8 (BSP parallel) |
| Size / thread | 7/16"-20 UNF female thread, 45 degree flare seat | G5/8 (5/8" BSP parallel) |
| Fitting form | SAE 45 degree flare, female | parallel pipe thread, regulator side |
| Seals on | mates against a male 45 degree flare face | flat washer on the face of the inlet |
| Rating / role | the female half of the homebrew flare standard | a common regulator inlet thread that a CGA-320 or W21.8 adapter presents |
Questions and answers
How do FFL and G5/8 regulator inlet (G5/8 (BSP parallel)) compare?
FFL and G5/8 regulator inlet (G5/8 (BSP parallel)) differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.