Official Answer
Answer
Edge-winding involves bending flat wire on its edge, which significantly work-hardens the material before it is even formed into waves. This increases the initial tensile strength but reduces the remaining ductility. For materials like 302 SS, the modulus $E$ can shift slightly, and the internal residual stresses $\sigma_{res}$ must be relieved through a stress-relieving heat treatment (e.g., $315^\circ C$ for 30 minutes). If not relieved, the 'Springback' is unpredictable, leading to inconsistent free heights $H$ and loads $P$. The design must assume the 'as-heat-treated' properties for accurate load prediction.
