Firestone pin-lock keg post (gas 9/16"-18, liquid 5/8"-18)
Where gas 9/16"-18, liquid 5/8"-18 is used, its real dimensions, and how to connect it to other keg fittings.
Published dimensions
- Designation
- gas 9/16"-18, liquid 5/8"-18
- Size / thread
- gas post 9/16"-18 UNF, liquid post 5/8"-18 UNF (different sizes)
- Fitting form
- UNF male post thread
- Seals on
- poppet inside the post; post base O-ring seals to the keg lid
- Rating / role
- Firestone, Challenger and Super Challenger pin-lock kegs
Used on: Firestone V/VI Challenger and Super Challenger pin-lock corny kegs.
Firestone pin-lock posts break the usual rule: the gas post is 9/16-18 and the liquid post is 5/8-18, so the two posts on one keg are different threads. Buy the gas and liquid replacement posts separately and do not swap them, or a poppet will not 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: Homebrew Finds keg post thread size reference (per-maker gas/liquid threads)