split-ring

A split-ring is a type of metal ring made from a single coiled wire that overlaps itself, creating a double layer that items can be threaded onto by working them around the spiral.

The most familiar example is the ring used to hold keys on a keychain.

Split-rings are valued because items cannot easily slip off as they might from a simple closed ring.

The term also describes a type of fishing lure connector and certain jewelry findings.