Electrical discharge machining (EDM) machines can be roughly divided into four categories:

The first category is mainly used for machining various molds, cavities, and holes, accounting for about 80% of all EDM machines;

The second category is wire-cut EDM machines, used for cutting parts and processing punches;

The third category includes EDM machines that have both linear feed motion and rotational motion of the tool electrode relative to the workpiece, such as EDM boring and thread grinding machines;

The fourth category consists of EDM machines that can perform surface treatment on workpieces, such as electrical discharge engraving.

With the improvement of EDM technology, EDM machines have also developed significantly, such as the widespread use of rectangular wave pulse power supplies, along with the development of various superimposed waveform pulse power supplies and various derived rectangular wave power supplies. In terms of automatic gap adjustment, it has evolved from measuring and controlling only the electrode gap to adaptive control of multiple parameters. All these improvements and developments have ushered EDM into a new stage.