Extension spring
Coil spring for tensile force
Extension spring
An extension spring is a coil spring that generates a counterforce for tensile force. The force of the extension springs increases linearly based on the stretched distance. The extension spring differs from compressed coil springs in that the extension spring itself may have initial tension. Initial tension means that the extension spring must be stretched with a specific force before it starts increasing in length. Extension springs are used in, for example, door locks and agricultural machinery.
Extension spring characteristics
- extension springs have a linear spring rate
- generate a counterforce for tensile force
- can be made with German hooks or English loops
- can also be made with high hooks for narrow attachment points
- a narrow section of straight wire can be put in the middle of a spring; these are used for example in brake springs
- materials include spring steel, oil-quenched spring steel and galvanised, stainless and acid-proof spring wire as well as other special steels, such as heat-resistant spring steel
- wire diameters can range between 0.2 and 20.0 mm