In this video, we review the basics of retaining rings and how they work in assemblies. For more information on this, visit "www.motioncontroltips.com/sele..." www.motioncontroltips.com/sele.... Retaining rings hold components in assembly bores or onto the ODs of shafts by engaging machined grooves. In short, they create a removable shoulder preventing components from migrating from their proper position during operation. As with other joining hardware, such as cotter pins, screws, and bolts, retaining rings prevent mating components from excessively moving.