6. Electrode wear
Sinker EDM is a kind of machining of transcribing the shape of the electrode to the workpiece, and the shape of the electrode is damaged by sparks. This damage is called "electrode wear".
The ratio of the amount of machining of the workpiece and the amount of electrode wear is called "electrode wear ratio", and it is important on transcribing the shape of the electrode to the workpiece. Electrode wear ratio changes due to "the combination of electrode and workpiece material", "the polarity of the voltage to apply", "the duration of the spark", and so on.
