Durable hard metal with the finest grain size. Long life/best resistance. 2-helical U-shape. Standard Life/good evacuation. 3-cutter, vacuum brazing and hard. For a quick breakthrough and good removal of large bore bodies. Long shaft. For breakthrough drilling. Suitable for openings with a diameter from 45 to 80 mm in concrete, brick, limestone, e.g. for external connections of cables or pipes. One-piece tool, bell-shaped drill head with asymmetrically arranged hard metal pins and center carbide cutting. Large conveyor spiral, conical shaft. Note: Masonry pilot drill bit always in suitable hammer classes, since overload risk. Operating instructions for the drill hammer. 55 x 55 x 600 mm