Nitinol memory spring contracts on its own when tossed in hot water or heated by other means, returning to its original form.
Memory spring provides up to 2.5N (250 grams) force upon contraction.
Pull the spring open when cold with less resistance, heat to have it contract by itself.
One way memory with hooks. 0.75mm wire diameter. 6.5mm OD. 21 coils.
Description
Nitinol memory spring can be stretched at room temperature or below, and upon heating to 45C or above (113 F+) it spontaneously contracts to its original form, exerting force. This small spring can provide up to 250 grams of pulling force without risking permanent deformation to the spring (operation within 150 grams of tension is recommended for longevity).