Torsion springs :
Torsion springs are a specific type of spring that reacts to rotational forces called torque. A torsion spring exerts torque in a circular or rotating arc with the spring arms rotate about the central axis. The stress is in bending, not in torsion. This type of wire spring is most often used with forces of rotation similar to those found in a motor or drive unit with a rotating shaft or something as simple as a clothespin. In either application the wire is formed to provide resistance to torque, thus the name torsion spring.
Material Grade used :
IS 4454 Gr-2, EN-42, EN-45, EN-47, SS-304, SS-316 etc.