How does the 'Edge Contour' of a cold-rolled flat wire spiral ring affect its performance compared to a stamped ring?

Spiral retaining rings are manufactured by coiling flat wire that has been cold-rolled from round wire. This process produces a natural 'round edge' contour on all sides of the wire. In contrast, stamped rings have a 'burr side' and a 'break side' resulting from the die-cutting process. The rounded edges of the spiral ring reduce stress concentrations in the groove and prevent the 'scoring' of the shaft or housing during installation. Furthermore, the grain flow in a coiled spiral ring is circumferential, following the shape of the part, which provides superior fatigue resistance and higher structural integrity compared to the transverse grain flow found in many stamped rings.