This double cut ball carbide burr is perfect for hollowing and shaping an area, while also used to form concave cuts on various materials. Materials include ferrous metals such as steel and cast iron, nonferrous metals such as brass and copper and a variety of hardwoods. Individually packaged in a plastic tube for protection. Stocked with 12" long shank, for harder to reach areas, that is engraved with the part number and manufacturing quality control number.