What is the failure signature of a spiral retaining ring that has 'Dished' excessively before failing?

The failure signature of an excessively dished ring includes: 1) A permanent 'conical' shape to the ring when removed, 2) Wear marks only on the inner edge of the ring's face and the outer edge of the groove's back-wall, and 3) A 'rolled' or rounded edge on the housing groove. This indicates that the axial load exceeded the groove's material yield strength or the ring's bending stiffness. Forensic analysis involves measuring the 'dish angle.' If the angle is $>5°$, the assembly was significantly overloaded. The fix involves increasing the groove depth $d$ or using a higher-strength housing material.