Heating a bearing in the microwave

Whatever your parents told you, many metals are actually microwave safe.
I'm using an old bearing to demonstrate
A microwave doesn't create heat, the microwaves excite water molecules.
So as you excite the water in the paper towel, it vibrates and then heats up and evaporates at 100 deg. C and anything it is touching is absorbing that heat.
So the bearing is heated from the water/steam
Heat the bearing to about 200°F (90 °C)