Is a toaster a magnet

Commonly a toaster will have a small magnet as part of the time/colour mechanism.

A bimetallic strip gradually heats up, and breaks the electrical current.

If we use a simple bimetallic mechanism, then the breaking process will be gradual. If we add a small magnet to the system, then it will withstand the opening force of the bimetallic for a little, and then will snap open quickly.

If the breaking process were gradual, then there would be some arcing of the contacts - undesirable.