Below is a list of EDM Cutting manufacturers from El Cajon, California. EDM cutting, a process known as wire EDM, is the most effective method of making incisions into hard or soft metals to form many different products. The process is used to cut hard metals and other materials that are difficult to machine. The material being processed is eroded away using electrical discharge sparks from a wire made of brass, zinc, copper or tungsten. No actual contact between the wire and work piece occurs, but the sparks produced as a result of electrical conductivity wear away the material in the desired pattern.