... 1.EDM electrodes are made of carbide.Increase the surface of ferrous metal up to HV1100-1400 (HRC70 ... resistance, extend usage life 1-3 times. Mainly for surface hardening, like cold stamping, forging & pressing, bending, ... work pieces. Characteristic of XKS-350 Electro spark intensify machine 1.portable power, portal type, easy ... stock XKS-350 Electro spark intensify machine, surface harden machine