A compressed spring (also called a compressive spring) is a helical spring that bears compressive loads. The cross-section of the material used is mostly circular, but there are also rectangular and multi-strand steel coil varieties.

The spring generally has a uniform pitch, and the shapes of compressed springs include cylindrical, conical, convex, concave, and a small number of non-circular types. There is a certain gap between the coils of the compressed spring, and when subjected to an external load, the spring compresses and deforms, storing elastic potential energy. The product has a wide range of applications in electronics, motors, computers, information technology, automobiles, bicycles, hardware tools, gifts, toys, and even defense industries due to its design being easy to grasp and the manufacturing control being relatively simple.