Connect 5/8" BSP beer thread (shank / coupler) to 3/8" BSP shank thread
How to join 5/8" BSP (7/8"-14 nut) and 3/8" BSP (G3/8), and what stops it leaking.
Not compatible. 5/8" BSP beer thread (shank / coupler) and 3/8" BSP shank thread do not share a mating thread, so there is no adapter between them; fit the part that matches your hardware.
The two ends
- End A
- 5/8" BSP beer thread (shank / coupler) (5/8" BSP (7/8"-14 nut))
- End B
- 3/8" BSP shank thread (3/8" BSP (G3/8))
- A seals on
- flat nylon or fibre washer on the face of the thread
- B seals on
- flat washer on the thread face
- Part needed
- matched replacement, no adapter exists
The part to buy
5/8 BSP and 3/8 BSP are different threads, so a 3/8 tail will spin loose in a 5/8 shank and a 5/8 tail will not start in a 3/8 one. There is no adapter that makes them mate directly; you fit the push-fit stem or tail whose BSP size matches the shank you have.
In a listing the two look almost identical and both are called BSP beer thread. Measure the shank or confirm the part number before buying. A 3/8 BSP stem in a 5/8 shank is the classic mail-order mistake.
Related connections
Sources: KegLand Duotight 8mm x 5/8 BSP (keg couplers and tap shanks) · ISO 228-1 (G / BSP parallel pipe threads) · The Malt Miller John Guest 3/8 to 5/8 BSP shank adapter (PI451215FS)