FFL vs GU Thread Adapter: specs compared
Updated 05 September 2026.
5
specs differ
FFL and GU Thread Adapter differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | FFL | GU Thread Adapter |
|---|---|---|
| Designation | 1/4" FFL (7/16"-20 UNF) | 13/16"-14 to 7/8"-14 |
| Size / thread | 7/16"-20 UNF female thread, 45 degree flare seat | 1/2" BSP (13/16"-14) one end, 5/8" BSP (7/8"-14) the other |
| Fitting form | SAE 45 degree flare, female | port thread adapter |
| Seals on | mates against a male 45 degree flare face | flat washer on each threaded face |
| Rating / role | the female half of the homebrew flare standard | converts the 1/2" BSP (13/16"-14) beer port some G and U couplers carry to the 5/8" BSP (7/8"-14) standard |
Questions and answers
How do FFL and GU Thread Adapter compare?
FFL and GU Thread Adapter differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.