| Extension Springs are designed to absorb and store energy as well as create a resistance to a pulling force. It is initial tension that that determines how tightly together an extension spring is coiled. This initial tension can be manipulated to achieve the load requirement of your particular applications. All JM Steel's extension springs are wound with an initial tension is equal to the minimum force required separate adjacent coils. Each spring is of the constant diameter type with a variety of hook/loop styles | 
