Threaded fasteners are too bulky for tight spaces. Snap rings solve this by locking components in place using a tiny groove. There are internal snap rings for bores and external ones for shafts. Each has small holes at the open ends to fit snap ring pliers. They are commonly found in transmissions, CV joints, and universal joints. When installing them, make sure they spin freely in the groove. If they do not, dirt or burrs are blocking the seat, which can cause the ring to pop off under load.
Mechanic Glossary
Snap Ring
A spring-steel retaining ring that snaps into a machined groove on a shaft or inside a bore to prevent components from sliding out of position.
Frequently Asked Questions
Generally no. Snap rings lose their tension when stretched or compressed during removal. Install a new one to prevent failures.
Many snap rings have a sharp stamped edge and a rounded edge. The sharp edge should face the direction of thrust or pressure to prevent it from sliding out.
You will hear a distinct snap, and you should be able to rotate the ring in its groove with a small pick or screwdriver.
They are names for the same type of fastener. Snap ring usually refers to rings with eyelet holes, while circlips may not have them.