Answer
Edge-winding is the process of coiling a flat wire on its edge to form a ring, as opposed to stamping a ring from a sheet. Metallurgically, this is advantageous because the grain flow of the material follows the circumference of the ring. This circumferential grain orientation significantly improves the toughness and fatigue resistance compared to stamped rings, where the grain flow is linear and creates 'weak spots' where the grain is transverse to the stress. Additionally, edge-winding is a 'no-waste' process, making it more cost-effective for expensive alloys like Elgiloy or Hastelloy. The absence of a 'burr' (common in stamping) also reduces the risk of stress concentrations and simplifies the installation into precision-machined grooves.
