What Is EDM Machining?

EDM is a machining method mainly used for hard alloys or metals that cannot be machined by traditional techniques. However, a key limitation is that EDM is only applicable to conductive materials. EDM (Electrical Discharge Machining) is especially suited for cutting complex contours or delicate cavities that are difficult to machine with grinders, end mills or other cutting tools. Metals that can be machined with EDM include Hastelloy, hardened tool steels, titanium, carbides, Inconel and Kovar.

EDM is sometimes called "spark machining" because it removes metal by creating a series of rapid, repetitive electrical discharges. These discharges are passed between the electrodes and the metal piece being machined. The small amount of material removed from the workpiece is washed away by the continuous flow of fluid. Repeated discharges create a series of progressively deeper pits in the workpiece until the final shape is produced.