Method of manufacturing flat wire coil springs to improve fatigue life and avoid blue brittleness

摘要

The present invention relates to a method of forming a coil of spring wire by winding a wire into a coil spring formed of a plurality of rings of the wire wherein each of the rings has a substantially constant strain rate. The forming speed of the wire being wound is controlled so that each of the rings has a substantially constant strain rate and minimum work hardening occurs.