2. What kind of shape can it process?
EDM is called "a machining method by copying. It needs an original shape called "electrode". "Electrodes" are made with materials such as copper by different type of machine tools.
By hitting sparks intermittently to 1000 - 100,000 times per second between the electrode and the metal, it carves a shape of the electrode to the metal. Several hours later (depending on the size of the electrode), a shape of the electrode is copied on the metal.
