Official Answer
Answer
A spiral retaining ring is made from coiled flat wire, which means it has no 'ears' or lugs, providing a full $360°$ contact surface. The shear capacity $P_s$ is calculated as $P_s = _x000c_rac{D imes T imes ext{π} imes ext{τ}_s}{FOS}$, where $T$ is the total ring thickness and $ ext{τ}_s$ is the shear strength of the material (approx. $0.6 imes UTS$). Unlike stamped circlips, which can have stress concentrations at the lug holes, spiral rings distribute the shear load uniformly. However, for multi-turn rings, the calculation must ensure the load is shared across all turns, which requires the groove to be deep enough to support the entire radial wall $b$ of the ring.
