Retaining rings are designed to fit into a machined groove either on the inside of a bore or on the outside of a shaft. These components reduce vibration, retain two parts of an assembly, and can withstand axial loading. They are used in assemblies as a cost-saving solution, to avoid machining a shoulder onto a mating component.  Retaining rings exist in many forms including, stamped, spiral or Spirolox, constant section, hoop, e-clip, beveled, and wave-ring forms.The primary retaining ring type can be internal or external. Internal retaining rings fit into a housing or bore. External retaining rings fit over a shaft or pin.