Compression Springs General Data: A compression spring is an open-coil helical spring that offers resistance to a compressive force applied axially. Compression springs are usually coiled as a constant diameter, though they can be coiled in other needed forms such as conical, concave (barrel), convex (hourglass), or various combinations of these. The functional design characteristics of the spring should be given as mandatory specifications. Secondary characteristics, which may well be useful for reference, should be identified as advisory data. This practice controls the essential requirements, while providing as much design flexibility as possible to the spring manufacturer meeting these requirements. Spring Team always verifies incoming designs to insure manufacturability and informs customers when designs are over stressed or are not capable of being produced. Designs are always verified using SMI's (Spring Manufacturers Institute) most current released computer design program and our engineering department will gladly share the derived printouts with those interested. Spring Team has a design handbook which we will gladly ship out to your technical/engineering team to assist in their spring development needs.