Official Answer
Answer
If the face of the retained part (e.g., a gear or bearing) is not parallel to the retaining ring, the axial load $P$ is applied asymmetrically. This creates a point-load rather than a distributed load, which can exceed the local shear strength of the ring or the bearing strength of the groove. The resulting moment $M = P \cdot e$ (where $e$ is the eccentricity) induces high bending stresses in the ring, leading to 'Dish-out' at loads far below the theoretical maximum. Designers must ensure that the part contacting the ring has a flat, square face, or use a 'back-up washer' to normalize the load distribution.
