Patent ID: 7723635

Claim:
An electrode wire for electric discharge machining, comprising: a core; a covering layer formed on a periphery of the core; and grains formed on the covering layer, wherein the grains comprise a copper-zinc alloy including about 0.01 to 0.5 weight % of at least one additive element selected from the group consisting of aluminum, tin, magnesium, lanthanum, cerium, nickel, manganese, titanium, and zirconium, wherein the core comprises copper and a trace of unavoidable impurities, or comprises about 10 to 40 weight % of zinc, with the balance being of copper and a trace of unavoidable impurities, wherein the covering layer comprises about 37 to 49.5 weight % of zinc, with the balance being of copper and a trace of unavoidable impurities, wherein the grains comprise about 49.5 to 58 weight % of zinc, and about 0.01 to 0.5 weight % of the at least one additive element, with the balance being of copper and a trace of unavoidable impurities, and wherein the grains are spaced from one another on a periphery of the covering layer and the covering layer is formed between the grains to surround the grains.