Drilling tool particularly impact drilling bit for rock and reinforced concrete, which is used with high performance hand tool machine, has helical shaft, where one-piece hard material head is fixed on axial shaft end

摘要

The drilling tool (1) has a helical shaft (2), where a one-piece hard material head (4) is fixed on an axial shaft end (3). The hard material head has four cross-shaped radially extending shanks with two diametrically opposite major cutting edges (6). Auxiliary cutting edges (7) are also provided, which run from an outgoing drill bit (8) axially monotonous up to a radial external edge. A cladding surface (9) of another cutting edge lies completely within the cladding surface of the major cutting edges and affect only at the drill bit.