Tension springs are stressed in shear but are “pulled” rather than “pushed”, in order to effect energy transfer. By virtue of this they have different end forms to anchor them and to effect the actuation of the energy stored. The form of the ends is varied and virtually infinite in shape to suit the user and the application. However there are a number of standard or commonly used shapes. Tension springs are usually close coiled.

Wire Size :  0.3mm onwards to 10mm.
Material :  Round – Spring steel wires & stainless steel wires, and also Pb wires.
Ends :  There is a large variety of end types that can be put on a tension spring including machine loops, extended loops, double loops, tapers, threaded inserts, hooks or eye lets at various positions, extended hooks.