Shakti Spring is an extension spring manufacturer specializing in custom extension springs and custom extension spring ends which include machine loop and crossover loop ends, among other options to accommodate different tensions.

Extension springs absorb and store energy by offering resistance to a pulling force. Various types of ends are used to attach the extension spring to the source of the force.

Most extension springs are wound with initial tension. This is internal force that holds the coils tightly together. The measure of the initial tension is the load necessary to overcome the internal force and just start coil separation.