Patent ID: 7296497
Filing Date: 2007-11-20
Classification: B21C,Y10T

Abstract:
1. Method for manufacturing a drill blank or a mill blank by extrusion, said method comprising the forming of a first blank portion having external, axially extending external flutes and the forming of a further blank portion in the shape of a shaft, comprising: extruding a first blank portion having a free end and external flutes such that the free end and an adjacent portion of the first blank portion are extended into a cavity; sealing said cavity in the area of the free end of the first blank portion; further extruding mass to the cavity, said supply of extruding mass completely filling out the external flutes of the first blank portion to produce a second blank portion integral with the first blank portion; terminating said sealing to allow the second blank portion to be pushed out of the cavity; extruding a desired length of the first blank portion; and cutting off the first blank portion at the end facing away from the second blank portion.