US Patent 8182186 Screw

A screw (11) has a shaft (12), a thread (13) which is arranged in at least some areas over the circumference of the shaft (12) and which defines a helix (14), and cutting bodies (26; 36; 46; 56, 66) made of a material having hardness greater than the hardness of the thread (13) and arranged in recesses (20, 21) of the thread (13), with the cutting bodies (26; 36; 46; 56, 66) having their longitudinal extension oriented along the helix (14) so that their longitudinal axes (27; 37; 47; 57, 67) enclose an angle (A; B; C; D, E) of −35° to +35° with the respective tangents of the helix (14).