Structural features: the spring is a mechanical and electronic industry, widespread use of an elastic element, a spring contained in the subject can produce a larger elastic deformation, mechanical work or the kinetic energy is converted to deformation energy, while the deformation of the spring after unloading disappears and reply undisturbed, the deformation can be converted into mechanical power or kinetic energy. Carbon spring steel, alloy spring steel, stainless spring steel. The spring is an elastic mechanical parts to work. Usually made of spring steel. To control the movement of parts, ease the shock or vibration, lay aside energy, measuring the size of the force, are widely used in machinery, instruments. The compression spring is a coil spring, to bear the axial pressure spring contraction deformation when subjected to external load, save for the deformation energy.