Tension springs are helical wound coils that usually have hooks, loops, or end coils that are pulled out and formed from each end of the body. The function of an extension spring is to provide extended force when the spring is pulled apart from its original length. When there is no load, The coils of the tension spring are generally tight and there is no gap between the coils.

Materials

Music wire, alloy spring steel, stainless steel etc.

Dimensions

Outside Diameter, Inside Diameter, Wire Diameter, Free Length, and Extended Length

The Free Length is the length of a spring in the unloaded position (measured from inside the end loops).

The Extended Length is the length at full rated extension.

Finishes

Zinc/ Gold irritate/ Passivated/ Black Oxide/None

Ends

The hook types include Machine Hooks, Cross Over Center Hooks, Side Hooks, Extended Hooks, and Double Loop Hooks.

Application

Extension springs are used in trampolines, push and pull levers, rocking horses, screen doors, farm machinery, and anywhere else extended force is necessary.