3/8" BSP shank thread (3/8" BSP (G3/8))
Where 3/8" BSP (G3/8) is used, its real dimensions, and how to connect it to other keg fittings.
Published dimensions
- Designation
- 3/8" BSP (G3/8)
- Size / thread
- 3/8" BSP (G3/8) parallel
- Fitting form
- parallel pipe thread
- Seals on
- flat washer on the thread face
- Rating / role
- the smaller UK dispense thread on some shanks, John Guest stem adapters and inline taps
Used on: the back of some UK tap shanks and the thread on 3/8 push-fit stem adapters.
3/8 BSP is the smaller sibling of the 5/8 BSP beer thread. A 3/8 push-fit to 5/8 BSP adapter (John Guest PI451215FS) is the common part that takes 3/8 line up to a 5/8 shank. It seals on a flat washer, never on tape.
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: The Malt Miller John Guest 3/8 to 5/8 BSP shank adapter (PI451215FS) ยท ISO 228-1 (G / BSP parallel pipe threads)