Compression Springs are an open-coil helical spring that offers resistance to a compressive force applied axially. Compression Springs are usually coiled as a constant diameter-cylinder. Other common forms of Compression Springs such as conical, concave, (barrel,) convex (hourglass), or various combinations of these are used as required by the application. While square, rectangular, or special-section wire may have to be specified, round wire is predominant in compression springs because it is readily available and adaptable to standard coiler tooling. Compression Springs should be stress-relieved to remove residual forming stresses produced by the coiling operation. Kato Spring can produce Compression Springs with wire diameters of .005" - .320" in a variety of materials and specifications.