Nitinol spring 15-20mm / 30-40mm 2-way shape memory 15-20°C / 60-70 °C

Nitinol is a nickel-titanium alloy that has shape memory (SMA). This means that when a given temperature is reached, an object made of nitinol returns to the set shape.

Shape memory can be 1-way or 2-way.

1-way shape memory means that the alloy can be deformed at will and after reaching a given temperature it will return to a pre-programmed shape.

2-way shape memory means that the alloy has two pre-programmed shapes. For example, a nitinol spring with 2-way shape memory will shrink when heated and stretch when cooled. An analogous spring made from an alloy with 1-way shape memory will only shrink or only stretch when the temperature changes.

The spring from the offer has a two-way shape memory. This means that when heated, it will automatically expand, and when cooled, it will shrink back to its original size.

What is worth knowing about the use of nitinol?

A spring from the offer will be in a contracted shape at room temperature. By heating it to 60-70°C (e.g., by immersing it in a glass of hot water), we will cause it to expand to 30-40 mm from its initial length of 15-20 mm. The higher the temperature, the faster this transformation will take place. The spring will remain expanded as long as it is not cooled to a temperature of 15-20°C, at which point it will contract to its initial size.

A flame can also be used as a heat source, but be careful. Strong overheating of nitinol can partially or completely destroy the shape memory properties. Definitely avoid exceeding a temperature of 600-650°C. This corresponds roughly to the glow temperature.

Wires with small diameters react very quickly to a change in temperature - those with larger diameters react more slowly. The larger the diameter of the wire, the more force it will generate as it deforms.

Basic data of the product:

- spring length (cooled): 15-20mm

- spring length (heated): 30-30mm

- outer diameter: about 6.28mm

- transformation temperature (contracting): 15-20°C

- transformation temperature (expanding): 60-70°C

- wire diameter: 0.75mm