Standard external rings, sometimes called circlips or Seeger rings, fit into grooves milled into a shaft to help retain components within an assembly. They install using specialized tools that expand the ring and allow it to be slid into the groove on the shaft.

E-style rings, also known as E-rings or E-clips, have three prongs or fingers that snap into grooves on small diameter shafts to hold them in place, effectively retaining components and preventing parts from sliding out of the assembly. They feature wide shoulders with a larger opening than other ring types, allowing for higher thrust loads and installation from the side of the shaft rather than being slid along the shaft and into place.

Crescent rings, also called C-clips, feature a low-profile design that allows them to be used where clearance is limited. Their lack of teeth and shoulder height reduces their profile but also reduces their load capacity, compared to standard retaining rings.