Why Sodick uses ceramic on their EDM's

Alumina based ceramics are one of the "wonder materials" of the 21st century, with crystal alumina being the primary ingredient lending strength to sapphire. Introducing this high-strength insulating material into a machine provides significant improvements with regard to stable machining environments. With less than 1/3 the thermal distortion of steel and greater corrosion resistance than stone, Ceramics are the most reliable option for high-precision applications. (Click on Picture below for more information)