The EDM process we know today started with the observations of Joseph Preistly in 1770. He noticed that electrical discharges had removed material from the electrodes in his experiments. This is also known as electro-discharge erosion.

In the 1940's two Soviet researchers, the Lazarenkos', developed a machining process that formed the foundation for modern EDM.

Extrusion dies and blanking punches are very often machined by wire cutting. Cutting is always through the entire work-piece. To start machining it is first necessary to drill a hole in the work-piece or start from the edge. On the machining area, each discharge creates a crater in the work-piece and an impact on the tool. The wire can be inclined, thus making it possible to make parts with taper or with different profiles at the top and bottom. There is never any mechanical contact between the electrode and work-piece (see above). The wire is usually made of brass or stratified copper, and is between 0.1 and 0.3 mm diameter.

Depending on the accuracy and surface finish needed, a part will either be one cut or it will be roughed and skimmed. On a one cut the wire ideally passes through a solid part and drops a slug or scrap piece when it is done. This will give adequate accuracy for some jobs, but most of the time, skimming is necessary. A skim cut is where the wire is passed back over the roughed surface again with a lower power setting and low pressure flush. There can be from one to nine skim passes depending on the accuracy and surface finish required. Usually there are just two skim passes. A skim pass can remove as much as 0.002" of material or a as little as 0.0001". During roughing ( i.e. the first cut) the water is forced into the cut at high pressure in order to provide plenty of cooling and eliminate eroded particles as fast as possible. During skimming (accuracy / finish cuts) the water is gently flowed over the burn so as not to deflect the wire.