Electrical discharge machines use thermal energy to remove materials from a stationary workpiece to create desired shapes through rapid successive current discharges (sparks) between two electrodes. EDM machines are used on hard metal or electrically conductive materials. These machines come in three variants: die sinking, wire burning/spark EDM/wire erosion, and hole drilling. 

Die sinker EDMs comprise an electrode that sinks into a workpiece and uses spark erosion to create complex cavities with high precision on the workpiece, hence ideal for making molds and dies for a wide range of applications. 

Wire erosion EDMs use strands of wires to cut through the workpiece by creating electrical sparks between the wire and the conductive workpiece. Like the die sinker, the hole-drilling EDM comprises a tube-shaped electrode that uses electric charges to rotate through a workpiece to create holes.