Compression springs can be used as extension springs if assembled with wire forms called drawbars. Uses for this type of spring can vary, however drawbar extension springs are most commonly used when there is excessive deflection of a normal extension spring and breakage occurs.
Drawbar springs are designed at safe stress levels at the compression springs solid height. One of the key features of the drawbar spring is that the springs are designed in such a way that the drawbars prevent buckling as they are being compressed.
In addition, the drawbar spring has a hard stop at the compression spring’s solid height which makes it the optimal choice in applications where overload protection is necessary.