Enter what the mechanism has to do. The selector sizes every actuator form in the handbook against it and ranks what fits, at each of the four fatigue-life design levels.

Units
How is the part heated?
Motion
Duty
Output required
lbf
in
in

Ask for both and only the forms that work in both directions survive: an open pitch spring, or a Belleville carried either way.

Space available
in
in
in

Outside diameter is the hole the actuator has to drop into. Bore is the clearance something has to pass through it — a shaft, a bolt, a line. Leave it at zero when nothing does.

Temperatures
MinMax

Ambient is where the part must stay put. Degrees F.

Electrical
V
W
s

Power and heating time are the same equation from two ends. Leave one blank and the selector fills it in.

Cooling
s
What do you need from us?
pcs

We recommend ordering four times what you think you need. Prototypes rarely go to plan: parts get stretched past their limits in testing, designs change, and waiting on a second round of samples costs you days. No one has ever complained about having too much nitinol. Plenty of people have needed more, yesterday.

pcs
in

The spring length shown is the working coils only. Add whatever your crimp, hook or clamp needs, and it goes into the length to order.

Start from an application

What fits

Request a quote

How these numbers are worked out
Force comes from the design stress for the level you need — 100 MPa at a million cycles, 138 at a hundred thousand, 172 at ten thousand, 250 at a hundred — applied to the working cross-section. Motion comes from the matching strain, 1%, 2.5%, 5% and 7%, converted by the form: straight in tension, torsion of the wire in a helical spring, bending of the section in a torsion spring or a Belleville, shear of the wall in a torque tube. Heating time assumes all the electrical energy lands in the metal, which is optimistic; cooling is a lumped free-convection estimate and is the figure most worth testing. Every value is deliberately conservative, the same as the handbook. Ask us when your case sits near a limit.

Sized from the Handbook of Nitinol Actuators. Custom geometry, custom transition temperatures and forms outside this list: [email protected] · 1-855-583-5353