Spiral power springs are also named as clockwork springs because they are formed by winding flat steel. One end is fixed and the other end is subject to elastic deformation due to torque. Because the spring torsion is generated in a plane, the deformed angle and the torque will be in direct proportion. They are of non contact types and contact types. The external end of the spiral power spring can be fixed by means of hinge, pin, V shape or liner. We are able to design spiral power springs according to user's requirements on torque and space of use.