Design engineers are challenged daily to come up with economical designs that reduce weight, size, raw materials, and labor. This competitive mandate affects every facet of the design, including the fasteners needed to hold components in place. One style of non-threaded fastener that has been widely used to accomplish these goals is the retaining ring. Knowing which ring to use in a given fastening situation can greatly contribute to the overall effectiveness and economy of a design. This whitepaper describes different retaining ring types as well as which ring is best suited for different applications.