(1) cold winding method: spring wire diameter d ≤ 8mm using cold winding method. Cold winding of the spring commonly used cold drawn and pre-heat-treated high-quality carbon spring steel wire, winding is generally no longer quenched, only low-temperature tempering to eliminate the internal stress of the winding.
(2) hot coiling method: spring wire diameter (d>8mm) of the spring is wound with hot coiling method. Spring coiled in the hot state, rolled into the quenching, medium temperature tempering and other treatments must be carried out.