Grinding tools and separating tools are used for cutting and processing materials such as plastic, wood or metal. After cutting metal, for example, a ridge is formed on the edges. This can be removed by hand or by machine using different tools. Many grinding tools and polishing tools are available for fine processing of the surface. If separating tools become blunt after a long period of use, they can be made ready for use again by using sharpeners. Grinding tools and separating tools are used in the construction of electrical equipment.