Official Answer
Answer
A tapered mandrel allows for the gradual and uniform radial compression of a spiral retaining ring as it is pushed into a bore. Manual installation using pliers can 'over-stress' the ring by localized bending at one point, leading to permanent set (plastic deformation). A mandrel ensures that the ring is compressed symmetrically. The mandrel's large end matches the bore diameter, and the small end is slightly smaller than the ring's free ID. This method is essential for 'Multi-Turn' rings where the high radial stiffness makes manual expansion/contraction difficult and risky for the operator's safety and the ring's integrity.
