Subscribe to a magazine

Progressive Coil Springs

Back to article View Gallery
3 of 5
Manufacturers may make a single coil spring somewhat progressive so it has a rising spring rate as it is compressed. This can be done by varying the wire diameter or the mean diameter over the length of the coil spring, or by changing the pitch spacing. Pitch is the center-to-center distance between adjacent coils on a spring. As the lower rate coils on a progressive spring collapse during compression, the overall spring rate rises as fewer active coils remain in action.