Electro-erosion is a machining technology that uses the erosive power of electric shocks. In wire erosion, a stretched wire is used as an electrode to cut or profile the work piece.
The wire has to be changed during the machining process, as it is subjected to wear, it might break and stop the machining The machines fit for this type of machining are called "electro-erosion machines", or in English EDM (Electrical Discharge Machining).
It has been created by Soviet Lazarenko in 1943, during any experiments on the wear of electrical contacts: by immersing them in oil bath to reduce wear due to sparks, it would create the opposite effect. Electro-erosion has been improved thanks to development of electronics. Due to its peculiar characteristics, it is now a technology commonly used in industry, and even in the production of moulds (especially for plastic components), where the presence of deep cavities makes the machining difficult and sometimes impossible by using conventional milling techniques.