How it connects
Tube is pushed fully over the insert fitting's barbs; the ring is positioned about 1/8-1/4 in from the tube end over the barbs and its ear is squeezed closed with a cinch tool, shrinking the band so the tube seals on the barbs.
Male and female halves
Neither male nor female itself; it grips the outside of the tube that sits over the male barbed insert. The tube+ring forms the 'female' side around the male PEX insert barb.
Usually connects to
- Matching CTS PEX tube exterior (ASTM F876/F877) over a male insert barb
- Matching ASTM F1807 metal/brass insert
- Matching ASTM F2159 plastic/poly-alloy/PPSU insert
Common sizes
- CTS PEX sizes commonly 3/8, 1/2, 5/8, 3/4 and 1 in, with some lines reaching 1-1/4 in.
- Example ring markings: PEX 17.5 for 1/2 in, 23.3 for 3/4 in and 29.6 for 1 in; band widths about 7–10 mm.
- Tube ODs: 3/4 in = 0.875 in (22.2 mm), 1 in = 1.125 in (28.6 mm).
Where it is used
residential plumbingradiant floor heatingwater supply linespotable water distributionhydronic / radiant heatingcommercial potable water
Variations
- F2098 stainless pinch/cinch ear clamp
- Tabbed/positioning clamp with guide ring
- Generic metric single-ear hose clamp (check suitability)
- F1807 copper ring (different, crimped around its circumference)
How to recognise it
Narrow 304 stainless ring with one raised 'ear' (often with a slot/window) and small embossed dimples or square tabs on the band; usually stamped 'PEX' and a size number (e.g. 17.5). Sits on PEX tube next to a brass or poly barbed fitting.
Often confused with
| Confused with | How to tell them apart |
|---|---|
| PEX copper crimp ring (ASTM F1807) | Crimp ring is a plain copper ring compressed uniformly by a crimp tool; cinch clamp is stainless with a raised ear that is pinched. |
| PEX-A expansion ring (ASTM F1960) | Expansion ring is a PEX plastic sleeve, used with expanded tube and wide-shouldered fittings, no metal ear. Expansion uses a PEX/plastic sleeve stretched over the tube end, no metal ear. Expansion rings are PEX-a plastic sleeves, not metal clamps. |
| Generic automotive ear hose clamp | Same form; PEX ones are marked PEX and sized to CTS tube OD. |
| PEX copper crimp ring | Crimp ring is a plain copper band without an ear, compressed uniformly by a crimp jaw tool. |
Also called
PEX cinch clampPEX stainless steel clamp ringsingle-ear stepless clampOetiker-style ear clampOetiker-style pinch clampPEX cinch ringSSC ring
Good to know
This is a clamp accessory of the PEX insert-fitting joint, not a mating port. Best modelled as clamp onto PEX tube OD over a 'Male PEX insert barb' connection rather than a new connector type.
Related connections
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