Sanke M coupler (type M) vs Tr21: specs compared
Updated 05 September 2026.
5
specs differ
Sanke M coupler (type M) and Tr21 differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.
| Spec | Sanke M coupler (type M) | Tr21 |
|---|---|---|
| Designation | type M | TR21x4 (soda / SodaStream-style) |
| Size / thread | 5/8" BSP beer and gas ports, M-system probe | TR21 x 4 mm pitch trapezoidal |
| Fitting form | single-probe keg coupler | trapezoidal cylinder valve, external |
| Seals on | flat washer on each threaded port | O-ring on the valve stem |
| Rating / role | the M-system standard | small refillable soda-maker CO2 cylinders |
Questions and answers
How do Sanke M coupler (type M) and Tr21 compare?
Sanke M coupler (type M) and Tr21 differ on 5 specs: designation, size / thread, fitting form, seals on, rating / role.