Official Answer
Answer
'Dishing' is a failure mode where the retaining ring deforms into a conical shape under high thrust loads. This occurs when the groove wall yields or the ring's radial wall $b$ is too small to resist the moment created by the applied load $P$. Identification is simple: the ring appears 'warped' after removal. This deformation causes the ring to lose its grip on the groove bottom, eventually leading to it being 'ejected'. Troubleshooting involves checking the groove material hardness; if the groove is too soft, the ring will 'plow' into it. Solutions include using a 'Heavy Duty' series ring (thicker $t$) or hardening the groove wall to at least $30$ HRC.
