Compression Springs
Compression Springs are open-coil helical springs wound or constructed to oppose compression along the axis of wind. Helical Compression is the most common metal spring configuration. These coil springs can work independently, though often assembled over a guide rod or fitted inside a hole.
The springs are forced back to their original lengths and forms after the load is reduced or eliminated by the stored energy. When weighted, compression springs become more compact. In contrast to extension springs, compression springs' spiral wires do not contact when they are relaxed; instead, when stressed, they are tightly compressed.