FFL female flare (1/4") (1/4" FFL (7/16"-20 UNF))

Where 1/4" FFL (7/16"-20 UNF) is used, its real dimensions, and how to connect it to other keg fittings.

Published dimensions

Designation: 1/4" FFL (7/16"-20 UNF)
Size / thread: 7/16"-20 UNF female thread, 45 degree flare seat
Fitting form: SAE 45 degree flare, female
Seals on: mates against a male 45 degree flare face
Rating / role: the female half of the homebrew flare standard

Used on: swivel nuts on disconnects, the female side of check valves and inline shutoffs.

FFL is simply the female counterpart to MFL. An MFL screws straight into an FFL and the seal forms as the two flare faces meet. No washer is needed between two flares, only when a flare meets a flat metal port.

Flare fittings seal on the 45 degree flare face and must never be taped. Push-in fittings seal on an O-ring against the tube wall and need the tube cut square. Barbs seal under a worm clamp. Getting the sealing method right matters more than the thread label, because most homebrew leaks are a taped flare or an unclamped barb.

Connect this fitting

Connect MFL male flare (1/4") to FFL female flare (1/4")direct fit Connect Duotight 8mm push-in to FFL female flare (1/4")needs an adapter Connect Duotight 6.5mm push-in to FFL female flare (1/4")needs an adapter Connect John Guest 5/16" push-fit to FFL female flare (1/4")needs an adapter Connect Duotight 9.5mm push-in to FFL female flare (1/4")needs an adapter MFL male flare (1/4")related fitting (1/4" MFL (7/16"-20 UNF))

Sources: MoreFlavor thread types explained (MFL/FFL, NPT, BSP) · KegLand Duotight 9.5mm x FFL (7/16-20 UNF, 1/4 SAE) product data