Apel have invested in a new GF AgieCharmilles DRILL 20 and put the machine straight into production on its first order in November 2012. This little machine is a top of the range electrical discharge machining unit, which allows CNC-controlled highspeed vertical drilling to our manufactured aerospace components. What is Electrical Discharge Machining (EDM)? EDM (Electrical Discharge Machining) is an advanced manufacturing process that consists of two electrodes passing electrical discharges, through a piece of conductive metal. The intensity of the electrical discharges cut into the material or aerospace component, creating the desired shape quickly and with great precision.