Electrical discharge machining is a method of machining by creating electric sparks while metals is facing each other in a liquid such as water or oil, using the heat to melt the metal in a non-contact manner. Wire EDM and shape engraving EDM are machined by cutting. In wire processing machines, a thin wire is used as an electrode, and processing is performed like cutting. The shape engraving EDM produces electrodes in the form of a reversal of the shape to be processed, and processes (transfers) the shape of the electrode as if it was engraved on the object.