What is EDM machines?

Electrical Discharge Machining (EDM), also known as spark erosion, spark machining, die sinking, wire burning or wire erosion, is a manufacturing process whereby a desired shape is obtained using electrical discharges (sparks). Material is removed from the workpiece by a series of rapidly recurring current discharges between two electrodes, separated by a dielectric fluid and subject to an electric voltage. One of the electrodes is called the tool-electrode, or simply the 'tool' or 'electrode', while the other is called the workpiece-electrode, or 'workpiece'. EDM is commonly used to machine hard materials or those that would be difficult to machine with traditional techniques.