MFL male flare (1/4") (1/4" MFL (7/16"-20 UNF))
Where 1/4" MFL (7/16"-20 UNF) is used, its real dimensions, and how to connect it to other keg fittings.
Published dimensions
- Designation
- 1/4" MFL (7/16"-20 UNF)
- Size / thread
- 7/16"-20 UNF male thread, 45 degree flare seat
- Fitting form
- SAE 45 degree flare, male
- Seals on
- metal 45 degree flare face, never PTFE tape
- Rating / role
- the homebrew flare standard on regulators, manifolds and disconnect tails
Used on: CO2 regulator outlets, gas manifolds, shutoff valves, the threaded tail of most ball-lock and pin-lock disconnects.
The 1/4 inch label is nominal. The real thread is 7/16-20 UNF and it seals on the 45 degree flare face, not the thread, so tape or dope on the thread does nothing and can hold the flare off its seat.
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
Sources: MoreFlavor thread types explained (MFL/FFL, NPT, BSP) · KegLand Duotight 9.5mm x FFL (7/16-20 UNF, 1/4 SAE) product data · SAE J512 45 degree SAE flare (7/16-20 UNF) fitting reference