Types of Helical Compression Spring

A spring with closed ends and not ground is the most economical to manufacture and often performs well when the wire size is smaller than .020 and/or the spring index exceeds 12:1.

Closed and ground end springs offer better seating (squareness), which also influences how the axial force produced by the spring is transferred to its mating part, or the mechanism that it works in. Buckling is reduced when the ends of the spring are closed and ground.

Springs that are open and ground are usually produced this way when it is necessary to have a lower solid height and/or more active coils are required to affect the needed rate.

Springs with open ends, which are not ground, are normally produced this way when the solid height and rate are not an issue and where the design allows for more generous length tolerance. Open ends are also specified when the spring screws onto a threaded part.

Different End Available

Conical , Hourglass , Barrel-shaped springs are used in applications requiring a low solid height, increasing lateral stability or resistance to surging. Conical height can be designed so that each nests wholly or partly into an adjacent coil. Solid height can be as low as one wire diameter.

Variable Pitch springs are used to achieve a variable rate , or in dynamic applications where the cyclic rate of load application is near the natural spring frequency. As turn of lesser pitch become inactive during deflection, the natural frequency of a spring changes. Throughout the cycle , the spring has a spectrum of frequency response and not a single resonant frequency. Thus , surging and spring resonance are minimized.

Direction of Coiling

Spring Specification Diagram