Official Answer
Answer
Internal spiral retaining rings are installed by compressing the ring to a diameter smaller than the bore. This is done by 'winding' the ring, essentially reducing its circumference. Unlike stamped circlips, spiral rings do not have lugs for pliers. They are often installed using a tapered mandrel and a plunger. The mandrel compresses the ring as it is pushed through, and it snaps into the groove. Care must be taken not to over-compress the ring beyond its elastic limit, calculated by $S_{comp} = \frac{E t (D_i - D_g)}{(D_i - t) D_g}$, to avoid loss of 'cling' in the groove.
