Pneumatic die grinders are pneumatic tools that use compressed air to turn an abrasive stone for grinding (carbide bur, mounted point, etc.) at high speed to grind, cut, or polish. Micro grinders used mainly for deburring and chamfering in part and die machining, and micro grinder straight grinders for deburring and heavy grinding of welded parts have a compact handheld size and are also called portable grinders. A cylindrical grinding wheel is attached to the tip of the spindle, and that is turned at high speed for machining. They can be used for a wide range of uses including removing welding beads, chamfering, deburring, and finishing, and work can be done easily even on angled places and in narrow locations. There are also high-power types, quiet type, anti-slip and safety lever-equipped type, and other products where improvements have been made with easy of use at the worksite and people's safety in mind. There are many types, and selection can be made to fit different applications.