The electro-discharge process is made by a machine tool that uses the erosive power of electric discharge. This is one of the main processes involved in produce moulds for small metal parts. These mould have a lot of deep and narrow cavities that would otherwise be impossible to make by milling. Antoniana Minuterie has die-sinking and wire EDM machines. In the EDM plunge, a negative conductive material is repeatedly brought into contact with the piece to be eroded. A negative-shaped electrode is then created with respect to the shape of the machining to be obtained. Wire EDM instead uses a wire made of conductive material that is passed through a hole in the material and moved slowly to cut it. A great advantage of this technique is that based on an electro-chemical and non-mechanical principle it does not require the tool to have a hardness and a mechanical strength greater than the material to be processed.