Official Answer
Answer
Vibro-deburring (or tumbling) is used to remove any sharp edges or 'slivers' from the coiling process. While primarily for safety and ease of installation, it also improves the performance of the ring by creating a uniform radius on all edges, which reduces stress concentrations. For fatigue-critical applications, controlled tumbling can induce a small amount of compressive residual stress on the surface, similar to a mild shot-peening effect. This helps retard the initiation of surface cracks. However, excessive tumbling must be avoided as it can cause 'edge-rounding' to the point where the ring's contact area in the groove is reduced, thereby lowering the effective thrust capacity.
