How is the maximum thrust load capacity of a spiral retaining ring calculated based on shear?

The thrust capacity based on ring shear is calculated as $P_r = \frac{D \cdot T \cdot \pi \cdot S_s}{S}$, where $D$ is the shaft/bore diameter, $T$ is the ring thickness, $S_s$ is the shear strength of the material, and $S$ is the safety factor (typically 3). However, the overall system capacity is often limited by the groove material's yield strength rather than the ring's shear strength. The shear strength $S_s$ is approximately $0.6 \times$ the tensile strength of the spring material. For a 302 stainless steel ring with 160 ksi tensile strength, $S_s$ would be roughly 96 ksi. This calculation assumes the ring is properly seated and the groove has a square corner.