Not a direct fit. Joining John Guest 3/8" push-fit to Beer shank (7/8-14, 3/16 bore) needs a 3/8 push-fit to 5/8 BSP shank adapter. Sealing method, the real-world trap, and the exact part to buy.
Updated 05 September 2026.
Connect John Guest 3/8" push-fit to Beer shank (7/8-14, 3/16 bore)
How to join 3/8" (9.5 mm) OD and 7/8"-14 ends, 3/16" bore, and what stops it leaking.
Not a direct fit. Joining John Guest 3/8" push-fit to Beer shank (7/8-14, 3/16 bore) needs a 3/8 push-fit to 5/8 BSP shank adapter.
The two ends
- End A
- John Guest 3/8" push-fit (3/8" (9.5 mm) OD)
- End B
- Beer shank (7/8-14, 3/16 bore) (7/8"-14 ends, 3/16" bore)
- A seals on
- single O-ring plus stainless collet grab-ring
- B seals on
- beer nut and washer at the back, faucet coupling nut at the front
- Part needed
- 3/8 push-fit to 5/8 BSP shank adapter
The part to buy
A 3/8 John Guest line reaches a beer shank through a 3/8 push-fit to 5/8 BSP adapter: the collet grips the 3/8 tube and the 5/8 BSP end screws onto the shank against a flat washer. The shank is 7/8-14 on its ends, the same thread US shops call 5/8 BSP.
The 5/8 BSP end seals on a washer, so a weep at the shank means a missing or cut washer, not a loose thread. Do not tape a beer thread meant to seal on a washer, and confirm the shank is 5/8 BSP rather than the smaller 3/8 some inline taps use.
Related connections
Questions and answers
Connect John Guest 3/8" push-fit to Beer shank (7/8-14, 3/16 bore)?
Not a direct fit. Joining John Guest 3/8" push-fit to Beer shank (7/8-14, 3/16 bore) needs a 3/8 push-fit to 5/8 BSP shank adapter.