A circle cotter, also known as a cotter ring or split ring, is a formed

wire Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible strand of metal. Wire is co ...

fastener that is shaped like a circle, hence the name. The open end of the wire is in the middle of the cotter so when it is installed the inner tab is first installed in the hole. Because of this feature it is often used in applications where a sharp edge cannot be tolerated, such as fabric applications..

Kickout ring

A very similar type of fastener is the kickout ring, which bends the open tab upward instead of inward.

References

Fasteners {{tool-stub §