Characteristics

By far the most widely used type of spring, compression springs are designed to oppose compression and return to its uncompressed length when the applied force is removed. The potential applications for compression springs are limited only by the imagination.

Dimensions Measurement Guide

1. Hold the base of the spring in one hand, and the calipers in the other hand.
2. Place the calipers on the outside of the last coil, measuring the largest dimension. This is called the Outside Diameter (O.D.).
3. Place the calipers on the wire in the center of the spring. This is called the Wire or Material Size. You should also measure the wire toward one end for comparison and accuracy.
4. Place the calipers on the full length of the uncompressed spring. This is called Free Length.
5. Count the total coils, beginning at one end, just next to where the wire has been cut. Be sure you count all coils, including any portion of a coil. (see diagram for example)

Service Life

It should be noted that if critical force-versus-deflection linearity is required, only the center 60-80% of the available deflection range should be employed. Thus, reserve at least the first and last 15-20% of the range for potential spring-end and adjacent coil-contact effects. These effects can be largely ignored for the majority of spring applications.

Tolerances

Century Spring manufactures our stock springs to commercial tolerances, as defined by the SMI. Calculated rates and loads based on SMI geometric tolerances have an approximate +/- 10%. Low or high-index springs will have higher values. Compression springs characteristically have an hourglass shape when coiled on an automatic coiler; therefore, outside/inside tolerancing is applied to end coils only. This is an improvement consideration when selecting a spring that fits over a rod or inside a cylinder. Call us if tighter tolerance values are required for your application.

Direction of Helix (Wind)

The wind direction of our stock springs varies, both right-hand and left-hand wind. Stock springs are not sorted for wind direction. To order spring wound a specific direction, please contact our custom spring division.

E-mail:1176292201@qq.com