Spring is the use of the principle of elasticity to work mechanical parts, according to different types of spring needs. The torsion spring is one of them. Torsion spring it is the use of the principle of lever, through the material is soft, flexibility of the larger elastic material distortion or rotation, so that it has great mechanical energy is to withstand torsion deformation of the spring, its working part is each circle or close around or separated around. Torsional spring end structure is processed into various shapes of torsional arm, from single torsional to double torsional, and even various torsional bar deformation, can be shaped according to the design. Torsion spring is often used for balancing mechanism in machinery and is widely used in automobile, machine tool, electric appliance and other industrial production. There are many types of springs, such as stretch springs, compression springs, carbon nanometer springs, and so on.