ABSTRACT
Since Electric Discharge Machining (EDM) has been made available to industry, substantial improvements have been achieved from the point of view of overall machining efficiency throughout the last decades. Even by the fact that several classical machining methods are still more attractive in terms of machining speed, cost, and conveniency, “Deep Sinking” Electric Discharge Machining has its own application areas mainly in die making. In many cases, certainly for finishing and even polishing jobs, the preparatiion of the EDM tool is of the greatest importance. All the final geometrical information to be brought on the workpiece is initially present on the tool surface. It involves the final geometrical details of a three dimensional shape with accuracies up to a few μm. Spark erosion itself is a thermo-physical process dealing with electrical discharges occurring between an anode and a cathode. These sparks, which are randomly distributed all over the tool-workpiece contact area, have such a power density (105 to 107 W/mm2) that metal is removed by melting and evaporation.