Bench grinder

A bench grinder is like a machine that has two circular stones that spin really fast. You can put different things on the stones to sharpen or polish them. Imagine you have a pencil that has a dull tip and you want to make it sharp again. You can hold the pencil steady against one of the spinning stones on the machine and it will make the tip sharp again. Or if you have a metal tool like a screwdriver that has rust on it, you can use the bench grinder to polish it and make it shiny again. But you have to be very careful because the machine spins very fast and can hurt you if you touch it with your fingers. So always use it with an adult and make sure you don't get too close to the spinning stones.