Abstract
Is shown, that the electrical discharges in conditions of electric discharge machining (EDM) methods, introduced by electrospark (electroimpulse) machining, electromechanical machining, plasma machining and by an electrical arc sizing machining, have an identical physical nature is that is accepted to name by an electrical arc discharge or, that same, electrical arc. It unites these processes, makes by their sim- ilar, allowing to consider them in unity, correlation and interdependence, in particular, as alternative to tradi- tional processes of metals treatment by cutting and pressure. Differences of electrical discharges in condi- tions of various EDM methods realization is only different ways of an arc dynamic (mechanical) interaction with transversal to an arc pole by an environment-dielectric stream, which dynamic pressure on an arc pole determines power structure of an arc discharge, allowing to regulate an arc power performances in the widest conditions range. On a foundation of explained introducings the classification attributes and EDM methods classification are offered.