What exactly does the term EDM really mean? Electrical discharge machining has long been the answer for high accuracy, demanding machining applications where conventional metal removal is difficult or impossible. Much like processes such as laser cutting, EDM does not need a mechanical force in the removal process. This is the reason why it is considered non-traditional contrary to, for example, the processing with cutting tools. EDM machines typically fall within the following 3 categories:
The sinker EDM machining process uses an electrically charged electrode that is configured to a specific geometry to burn the geometry of the electrode into a metal component. The sinker EDM process is commonly used in the production of dies and molds.
Wire EDM is commonly used when low residual stresses are desired. Wire EDM has no added residual stress because it has no cutting forces. There is little change in the mechanical properties of a material in wire-cutting EDM due to these low residual stresses.
Hole Drilling EDM
EDM hole drilling works on the same technical principles as Wire EDM. Instead of wire, EDM hole drilling uses an electrically-charged metallic electrode tool that works much like a traditional drill bit for hole machining.