Stronger Material for Cold-Formed Coil Springs Used in Automotive Suspensions

Hot-formed coil spring material (SUP 190) has been developed in order to achieve weight reduction and corrosion fatigue strength and is currently used from the viewpoint of environmental protections⁽¹⁾. In the meanwhile, we have further developed a means of applying a high frequency induction heat treatment to the hot-formed coil spring material to create cold-formed coil spring material with features such as excellent formability and high shape freedom, as well as corrosion fatigue strength.

Consequently, a weight reduction of approximately 20% can be achieved in comparison with cold-formed coil springs using SAE 9254, which has been used up to this point.