... C. ISO/TS16949 approved About material of spring for valve spring Our spring have high elastic limit and fatigue ... reduce the elasticity. About usage of spring for valve spring Valve spring is made of steel wire spiral coils, ... process is not easy to deformation, this spring as valve reset device for the engine. About design of ... , BMW, Volvo, Citroen, Hyundai, Skoda, Peugeot, and so on valve spring