Compression spring set is the change in free height when a spring is first compressed and released. When the spring is first compressed, if the pressure in the wire is high enough at the point where the spring is compressed, the spring will not return to its original height and will be shorter after the first compression. This is called the compression spring "set" or "set" of the compression spring.
In compression spring design, there are two main ways to handle the change in free height due to the natural occurrence of compression spring set. Both of these methods should be considered in the design of the compression spring and they may affect the spring's manufacturing process and cost.
The following two methods are considerations for handling compression spring set.
Presetting or Removing Set
Presetting or removing the spring set from the spring is an additional manufacturing process where the spring is compressed to the set height to ensure the free height is correct for use. This process may add additional cost to the spring manufacturing process but may be a desired step depending on the application.
Allowed Set
When a compression spring is provided with a length longer than specified to compensate for the length loss when initially compressed, this is called "allowed set". "Allowed set" means that the compression spring is designed to compensate for the length loss when the spring is first fully compressed.
This loss of length can occur during the initial installation of the spring into the assembly. It is recommended to reduce costs on large orders that the spring be designed to "allow setting" so no secondary spring setting operation is required.
The new free length of a "set" compression spring will remain stable and consistent during subsequent compression cycles. The spring will not typically gain any noticeable additional set from subsequent compressions. There are many design considerations to review when using and designing custom springs. To learn more about spring design or to obtain more technical information, visit our Resource Center and download our Compression
Spring Design and Considerations and Compression Spring Basics for more information.
To calculate the coils of a spring, it is important to understand what is the active number of coils. The active number of coils generally applies to any portion of the spring that stores and releases energy. .
