Official Answer
Answer
The edgewinding process involves coiling a pre-tempered flat wire on its edge. This maintains a continuous longitudinal grain flow along the circumference of the spring. In contrast, stamping a wave washer from a sheet cuts across the grain structure at various points, creating 'weak' directions and increasing the likelihood of crack propagation from the edges. The edgewound spring's uniform grain orientation provides superior fatigue resistance and more consistent elastic recovery. Furthermore, edgewinding allows for 'Multi-Turn' designs without gaps, which is impossible via stamping, as the latter would require welding or complex overlapping that introduces stress concentrations.
