Electrical discharge machining (EDM) is a process of metal machining in which the EDM machine discharges thousands of microscopic sparks to a metal workpiece. The parts to be cut must be electrically conductive like mild steels, tool steels, stainless steels, titanium, super alloys, brass, copper, aluminium, carbide and many other metals. Instead of cutting the material conventionally by force the EDM process melts or vaporises it, leaving little debris and providing a very accurate cut. CNC programs are made up to provide the path for very intricate shapes that are sometimes required.