Torsion Springs

Torsion springs are the helical springs that exert a rotational force (torque). These springs are resistant to the rotationally applied force. A torsion spring works by twisting its ends along its axis.

A helical torsion spring is a wire in the shape of the helix and it is subjected to twisting about the axis of the coil when sideways forces are applied to its ends and result in twisting the coil tighter.