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NiTi • Nitinol 2-Way Memory Coil Spring

  • $ 25.00

Nitinol pre-trained 2-way memory helical/coil spring has the special feature of reacting to both heating and cooling. This particular version of the spring will expand on its own when cooled, and contract with force when heated. Two variants are in stock, optimized for different working temperatures.


This variant of the NiTi spring contracts when heated and expands when cooled.

  • Spring wire gauge: 1 mm
  • Diameter: 10 mm
  • Fully contracted (hot) length: 60 mm (excludes hooks)
  • Fully extended (cold) length: 120 mm (excludes hooks)
  • Maximum work (on contraction): ≈ 0.6 N (61 grams)
  • Maximum work (on expansion): ≈ 0.2 N (20 grams)
  • Weight: 3.1 grams

While the spring will provide force both in contraction (pulling force when heated), and expansion (pushing force while cooled), please note that due to the nature of nitinol, there is substantially more force in the austenite phase (when the spring is contracting).

Unlike linear actuators, spring design only uses nitinol's properties along the skin of the material. Do not expect excessive forces from these springs, however, they can find novel uses in actuators or devices that only require light work. One of these springs can perform up to 60 grams of work on contraction and 20 grams on expansion.

Purchase options

Select your desired Af (hot) / Mf (cold) of the spring. We have two varieties in stock at the moment:

  • Af 60 / Mf 30 - Spring will contract at around 60ºC, and will expand on its own at around room temperature. At a typical (warm climate) working room temperature of 25-30ºC, this spring will be expanded.
  • Af 40 / Mf 10 - Spring will contract with less exposure to heat (around 40ºC), but will need to be cooled more to expand on its own. At a typical (warm climate) working room temperature of 25-30ºC, this spring will be contracted. 

Frequent questions

Q: Is the reverse possible, where the spring expands when hot and contracts when cold?
A: Yes, absolutely. Please contact Nexmetal with your requirements.

Q: Are other diameters / wire gauge available?
A: Yes, we can produce to your specification. Order minimums may apply.

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