Shaping of drill tool bodies lays a cut length of an extruded cylinder body with straight inner recesses on a support surface to be twisted by a friction surface system to give inner helical recesses for sintering

摘要

To shape a cylindrical body with at least one inner helical recess, from a malleable mass and especially an extruded blank, the body is initially formed with an inner recess along a straight line. A length is cut to give the body (10), and it is supported over its whole length on a laying surface (16) and rolled by a surface friction system (18). The rolling speed varies in a continuous linear action to give the body a consistent twist. The surface friction (18) system acts on the body (10) along a line which is diametrically offset to the support line on the support surface (16). The twisted body is sintered.