EDM graphite electrode A, the high speed; Graphite discharge 2-3 times faster than copper, the material is not easy to deformation, obvious advantages on thin steel electrode processing, the softening point of copper in 1000 degrees, easy to produce because of the heat deformation, by contrast, only 1/30 of the copper graphite material coefficient of thermal expansion; Second, the light weight; The density of graphite is only 1/5 of copper, large electrode in EDM, can effectively reduce the burden of machine tools (EDM), more suitable for the application of large injection mould are; Three, small loss; Because the spark oil contains C atoms, in edm, high temperature lead to spark came out of the oil C atoms are broken down, and on the surface of graphite electrode form a protective film, compensate the loss of the graphite electrode;