Oscillating Weight or Rotor

The oscillating weight, also known as a rotor is a component that is found in the winding mechanism of self-winding watches.

It is a semicircular disc that turns in a free manner to wind the motor spring by making a pivoting movement which automatically winds the calibre’s motor spring.

The oscillating weight of a self-winding watch is very often made of stainless steel but also gold, platinum or tungsten carbide.

Oscillating PinionOscillator