Electrical discharge machining (EDM) is a manufacturing process that comprises the generation of an electric arc between a piece and an electrode in a dielectric medium to carve particles from the piece until the forms of the electrode are reproduced on it.
The process of thermal erosion extracts metal through a series of recurring electrical discharges between a cutting tool that acts as an electrode and a conductor piece, in the presence of a dielectric liquid. The heat of the discharge vaporises tiny particles from the material of the piece and the electrode, which are eliminated from the hole by the constantly flowing dielectric liquid.
The expansion of electrical discharge machining over the last 45 years has given rise to three main types: die sinking EDM, wire EDM, and hole drilling EDM. The first two are the most used.