Square end mills have a square nose and are rotated against a piece of stock to create a flat-bottomed groove with 90° inside corners in milling tasks. Also called square-nose end mills, they are used for counterboring, side and face milling, and milling square shoulders. Flutes on each of the end mills' cutting heads carry chips away from the workpiece to prevent damage to the end mill or workpiece. Square end mills are used on CNC or manual milling machines.