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Extension Springs

Extension springs are used to resist tensile axial loads and to absorb and store energy as well as create resistance to a pulling force. Springs can be wound as either an open or closed-coil. Closed-coil springs are usually manufactured with an 'initial tension' that must be overcome before deflection will occur. The initial tension can be varied to decrease as the spring index increases. Hundreds of different end configurations are possible for connecting the spring to the load; the most common are crossover, machine, and extended hooks.

Springs Inc. can produce custom extension springs for short or large quantity production runs in several materials and end types for either open or closed coil extension springs. When you work with Springs Inc, you get the dedicated resources of our experienced design team who will assist you with the selection of materials and calculations.

  • From conical to barrel shapes, springs can be formed with the ends that work for you.

  • We utilize tools from SMI when designing springs.

  • Helps your custom extension spring meet the spec.

  • Test new spring designs and improve product performance with rapid prototyping.


Common Materials

Spring Steel, High Carbon Steel, Low Carbon Steel, Nickel Plated Carbon Steel, Stainless Alloys, Non-Ferrous Materials, Elgiloy®, Hastelloy®, Monel®, Inconel®

Material Options

.007 In. to .005 In. in Wire Diameter, Round Wire

End Options

Conical, Barrel, Custom Diameters


Zinc, Gold Iridite, Black Oxide, Passivated, Shot Peening, Dykem®

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