Calculate the maximum allowable thrust capacity of a spiral retaining ring based on the shear strength of the ring material.

The thrust capacity based on ring shear $P_r$ is calculated using the formula $P_r = \frac{D \cdot T \cdot \pi \cdot S_s}{S_f}$, where $D$ is the shaft/bore diameter, $T$ is the ring thickness, $S_s$ is the shear strength of the material (approximately 0.6 times the tensile strength), and $S_f$ is a safety factor (typically 3). This calculation assumes that the groove is deep enough and the groove material is strong enough to prevent the ring from dishing. If the groove material yields before the ring shears, the capacity is limited by the groove yield formula $P_g = \frac{D \cdot d \cdot \pi \cdot S_y}{S_f}$, where $d$ is the groove depth and $S_y$ is the yield strength of the groove material.