Official Answer
Answer
Ring shear capacity $P_r$ is the load at which the retaining ring itself fails by shearing. It is calculated as $P_r = _x000c_rac{D imes t imes au_s imes ext{Safety Factor}}{\phi}$ where $t$ is the ring thickness and $\tau_s$ is the shear strength of the ring material (typically $0.6 \times \text{tensile strength}$). Ring shear becomes the limiting factor when the ring is installed in a groove made of very high-strength material (e.g., hardened tool steel) or when the ring thickness is very small relative to the groove depth. In most 'soft' housings like Aluminum or standard Carbon Steel, the groove will yield long before the ring shears. For aerospace 17-7PH rings, $\tau_s$ can exceed $150,000$ PSI.
