Official Answer
Answer
The axial load capacity of a retaining ring assembly is often limited by the groove material's yield strength, not the ring itself. The maximum thrust load $P_g$ based on groove deformation is $P_g = \frac{D · d · π · σ_y}{S_f}$, where $D$ is the shaft/bore diameter, $d$ is the groove depth, $σ_y$ is the yield strength of the groove material, and $S_f$ is the safety factor (typically 2). If the groove material is soft (e.g., aluminum), the groove wall will 'dish' or deform at loads much lower than the ring's shear strength. Engineers must ensure the edge margin (the distance from the groove to the end of the shaft) is at least 3 times the groove depth to prevent 'blowout' of the groove wall.
