What is the effect of a 'chamfer' on the mating component on the thrust load capacity of a spiral ring?

A chamfer or radius on the retained part (e.g., a bearing) reduces the effective contact area with the spiral ring and introduces a radial force component that promotes 'dishing.' The maximum allowable chamfer $c$ is typically limited to $50\%$ of the ring's radial wall $w$. If the chamfer is too large, the load is applied further from the groove wall, increasing the moment arm and leading to premature ring roll-out. In such cases, a 'backup washer' with a sharp corner must be placed between the chamfered component and the retaining ring to ensure purely axial load transmission.