Wire electrical discharge machining (EDM) is a process of metal machining where a tool discharges thousands of sparks to a metal work piece. Although this is a non-conventional process, wire EDM works on parts resistant to conventional machining processes and if these parts are electrically conductive; usually, they are non-ferrous, and include steel, titanium, super-alloys, brass, and many other metals. Instead of cutting the material, EDM melts or vaporizes it, producing comparatively small chips and providing a very accurate cut line.
This process is commonly known as Plunge, Ram or Sinker EDM. This process is often used when the desired cut or design feature does not penetrate through the entire work piece. Electrodes are mostly manufactured from graphite or copper tungsten. These electrodes are used to disperse the electric current. It runs along the metal piece, the anode, and the electrical current reacts to melt or vaporize the metal. As a result of the dielectric fluid, usually a hydrocarbon oil into which both the cathode and the work piece are immersed, the minute chips produced by the process wash away from the piece.