Expansion Springs
Definition - Wire springs with hooks on the ends which already carry an amount of tension in between its coils in order to keep them together and be used to store more energy when pulled apart by a force.
Expansion springs are commonly known as extension springs. There are 4 basic hook types which you can use for your extension springs; machine hooks, side hooks, cross-over-center hooks, or extended hooks. All of these hooks are made directly from the expansion spring’s coils except for extended hooks. Extended hooks are formed off the machine as the spring is. You can also choose to put no hooks on the spring and use them to be installed into a hole where the threads for a screw have worn out or use bolts instead of hooks for more resistance.


At The Spring Store, you can browse our extensive stock expansion spring catalogue and find exactly what you need for your project. Since these are ready-to-ship stock items, there’s no need to wait through long lead times—just the standard delivery time from your chosen shipping method.
Stock expansion springs are also ideal for prototyping during the testing phase of your project. Because they're available in retail quantities and at a fraction of the cost of custom-made springs, you can easily order several options to test and determine which one works best for your application. Please note that a small handling fee applies to orders under $25 USD.


If you can’t find your spring in stock, you may contact us via email or fill out a Instant Spring Quote form with your spring’s dimensions to have us provide you with a quote on making them custom. Both custom and stock springs have their pros and cons. Stock springs may be economical and easy to get but they work best in small quantities and you might not always find exactly what you’re looking for. Custom expansion springs, on the other hand, are manufactured to the dimensions you give us and are much more economical in larger production quantities.
Click here to get Instant Spring Quote (ISQ) of your custom spring!

