Special-shaped spring is to hook, straight hook, combined, multi-ring spring collectively, special-shaped spring with spring machine can be done directly, the so-called special-shaped spring, that is to say, his shape is irregular, it is not to say that the form is strange.

For the special-shaped spring with the same structure, under the same load, the stress of the spring with fewer effective rings or large spiral Angle obtained by the two methods is quite different.

This is because, with the increase of helical Angle and eccentric load, the lateral deformation of special-shaped spring diameter or larger, therefore the stress is bigger also, torsion bar using high purity of 45 steel, high hardness on the surface of the obtained with high frequency quenching and larger residual compressive stress, so as to improve the fatigue life and relaxation resistance, with the wide application of electronic products, special-shaped spring factory basically adopts the stamping and automatic bending forming, the main valve spring is joint to the development of composite material technology main development multistage shot peening and liquid nitriding process, to improve the surface residual compressive stress, improve the fatigue life.