In Electrical Discharge Machining (EDM) an electrical current is used to burn a desired shape into a metal part. In the EDM process a graphite electrode, made in the shape of the desired cavity, is slowly fed into a clamped workpiece that is submerged in a tank of oil. As the electrode is fed into the workpiece, a pulsed electrical D.C. charge is applied which causes sparks to jump from the electrode to the workpiece. These sparks remove steel particles which are washed away by the oil bath. This process will work on hard or soft metals that are able to conduct electricity. EDM excels at producing intricate, deep, ribbed mold cavity shapes. Shown here is a Computer Numerical Control EDM machine.
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