The spark erosion machine is a kind of electric discharge machine. It is used to create blind cavities and in situations where conventional milling machines or lathes are not possible, such as when sharp corners or materials that are particularly difficult to machine, then we need electrodes, and hexagonal sharp electrodes produce hexagonal shaped pockets. ​

Electric discharge machining is a manufacturing process in which a spark is generated by electric discharge to make a work piece into a desired shape.

Electrical Discharge Machining can be divided into three common types: wire EDM, sinker EDM, and hole drilling EDM.