How does 'Groove Radius' affect the seating and performance of a spiral retaining ring?

While a perfectly sharp corner in a groove would maximize the contact area, it creates a massive stress concentration factor $K_t$, which can lead to shaft/bore fatigue failure. Standard practice is to allow a small radius $R$ at the bottom of the groove. However, the ring has a 'natural radius' or 'chamfer' on its edges. If the groove radius $R$ is larger than the ring's edge radius, the ring will not seat fully at the bottom of the groove, leading to a 'wedging' effect that can force the ring out under axial load. The design rule is $R_{groove} \leq 0.1 imes ext{Groove Depth}$ to ensure proper seating.