spiral spring

sprial spring with thickness:0.15-20mm steel band.

This is a type of spring in which the wire or steel band is wound
into a plane helical. One end of the spring is fixed, while the
other end, once being subjected to a given torsion, will generate
an elastic bend deformation by which the spring will twist within
its plane. The more the turns, the larger the deformation angle,
and the higher the stored energy.