An alloy
like no other.


Actuator wire

Actuator wire is made with shape memory Nitinol, utilizing the material's ability to cycle between two different material phases. At room temperature, the wire is in its martensitic phase. By applying a load, the wire is elongated and can then actuate by applying an electrical current or other means of heat to achieve a phase transformation.

When heated beyond the transformation temperature, the material recovers, transforming to the austenitic phase, and the wire performs work - meaning that it returns to its original length - lifting or otherwise pulling on the load. As the material cools it returns to the martensitic phase and the load causes the wire to elongate again, ready to repeat the cycle.


Understanding the benefits

Nitinol's unique properties allow it to perform a surprising amount of work for its size. This means that actuator wire is smaller, lighter, quieter, and can be longer-lasting than more traditional actuators.


Typical end uses

Actuator wire is often used in industries with small spaces and where lightweight devices are required, such as:

  • Automotive
  • Aerospace
  • Active textiles
  • Consumer electronics


Design specifications

There are a number of considerations when using actuator wire in your applications. You can use this information to guide your conversation with our Engineering team.


Size ranges and operating parameters

Actuator wire is available on a spool or in discrete lengths, in various size ranges and actuation temperatures. Use our actuator calculator and the chart below to explore possibilities.

  Size range  
 Hysteresis width Stroke
wire on
a spool
0.0762 to 0.5842 mm
[0.003 to 0.023 in]
70 to 90 °C
[158 to 194 °F]
100 to 150 MPa
[14.5 to 21.75 ksi]
30 ± 5 °C 
[54 ± 9 °F]
4 to 5%

As and hysteresis width based on 150 MPa application stress. Recommended application stress values are for optimal actuation performance. Application stresses outside of this range can also be used depending on the design requirements of the actuator.

While we provide standard size ranges and operating parameters as a starting point, we're always looking for new ways to innovate. If you are interested in something outside what is listed, please contact your sales representative to discuss possibilities.


Key terms

Designing with actuator wire comes with some specific terminology. We've broken down a few of the most important terms below so you can share a common language when you speak with one of our engineers.

  • As is the austenite start temperature, and is also referred to as the "actuation start" temperature in actuator applications. This is the temperature at which the material transforms and performs work under a given load.
  • Application stress is a result of the amount of load or bias force imposed on the actuator wire in application. Optimal stress for product life is between 100 MPa and 150 MPa. The amount of stress applied will also influence actuation temperatures.
  • Fatigue life is determined using thermo-mechanical cycles, or the number of times the material can be thermally cycled between phases while under a certain applied stress.
  • Hysteresis width is the difference between the austenitic and martensitic transformation temperatures. This temperature delta corresponds to how quickly the actuator will reset after being heated for actuation.


Product forms and capabilities

In addition to actuator wire, you can take advantage of our additional processing and testing capabilities. Since actuator wire is tailored to your application, additional processing and testing are evaluated on a case-by-case basis. Reach out to your Sales Representative for more information.

  • Mechanical assembly consists of crimps, fittings, and specialized parts.
  • Thermomechanical testing
    • ASTM E3097 compliant thermal characterization under stress
    • Variable load with spring simulation thermal characterization
    • Material electrical response in various environmental temperatures

If you want to better understand how actuator wire works and its characteristics, download our Nitinol Actuator Wire Technical Information Sheet.