Double-end high-speed steel ball end mills have a rounded nose on both their ends and can accomplish more milling tasks than single-end 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. High-speed steel ball end mills offer good wear resistance for general purpose milling applications. They're more flexible and can absorb more shock and vibration than carbide, powdered-metal, or cobalt steel end mills. Also known as ball-nose end mills, ball end mills have a rounded nose and create a round-bottomed groove in milling tasks. They are rotated against a workpiece to make round-bottomed slots and pockets or mill complex shapes without sharp corners.