Walzgeschmiedeter Bohrer

摘要

A roll-forged drill bit 1 comprising a shank 3 for insertion in a chuck of a drill, the shank 3 including an helically twisted web 7 defining a cutting tip 9, the cutting tip 9 including a central chisel edge 11 and a cutting edge 15 defining the maximum diameter of the cutting tip 9, wherein the cutting tip 9 is formed after the shank 3 has been roll-forged and includes a pair of faces 13 defining the chisel edge 11 and a pair of upturned flats 17 defining the cutting edge 15. A roll-forged drill bit 1 according to the present invention provides a significant improvement in cutting speed over known prior art roll-forged drill bits.