Electrical Discharge Machining
Electrical discharge machining is a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks). This technique is used when mechanical machining is not possible as well as in case of extremely hard materials when turning or milling is not cost-effective.
With this method a material is removed from the work piece by a series of rapidly recurring current discharges between two electrodes separated by a dielectric liquid and subject to an electric voltage. This method is employed for manufacture of dies, press tools, punching dies, injection moulds and punches, as well as machine parts.
Electrical discharge machining offers high dimensional accuary regardless of shape of hardness of the workpiece. This method may be employed however in case of conductive materials only.