Double-end powdered-metal square end mills have a nose on both their ends and can accomplish more milling tasks than single-end square end mills before they need to be replaced. When the cutting edges on one nose wear down, the end mill can be flipped over to expose the fresh cutting edges on the other nose. Powdered-metal end mills are tougher and less likely to break than high-speed steel or cobalt square end mills. Also called square-nose end mills, 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. They are used for counterboring, side and face milling, and milling square shoulders.