Made of high quality high carbon steel, durable and corrosion resistant, long service life. By high frequency quenching heat treatment, high hardness. The counterbore is suitable for wood, plastic, other materials to form a low hardness holes. Suitable for cordless drills and hand screwdrivers with round socket, such as Hilti, Bosch, Makita, Hitachi, very good, AEG, Metabo, DeWalt, Black & Decker, Mannesmann brothers. The package includes a 12mm, 16mm and 19mm large size Countersink different can offer a variety of choices. The 12mm, 16mm and 19mm size counterbore is ideal for wood boards, fiberboard, particleboard, plywood, plastic, aluminum board, etc., to form holes. Universally applicable, reducing and deburring without Rattermarken.Verwendbar for DIY, home and public construction to development. Features: Material: Steel Size: 39mm x ca.12mm, 16mm x 42mm, 19mm x 44mm Turned Diameter: 6.00mm Package Content: 1*12mm countersink 1* 16mm countersink 1* 19mm countersink