Patent ID: 8080321

Claim:
A rust-preventive metal part comprising: a substrate, which is a steel wire to which wire-drawing processing is performed; and a rust-preventive coating film on a surface of the substrate; wherein the rust-preventative film comprises a first coating film, which is formed on the surface of said substrate and which comprises an inorganic-compound-containing coating film being free from chromium, a coating amount of said first coating film being 150-500 mg/dm 2 ; wherein the substrate is subject to a degreasing treatment prior to being coated with the rust-preventative film, said degreasing treatment including immersing the substrate in an alkaline solution with pH 10-13, so that a residual amount of zinc phosphate coating film or manganese phosphate coating film, which has been formed on the surface of said substrate at the time of said wire-drawing processing, is less than 25% of the surface of said substrate; wherein said first coating film comprises a silicate compound including a metallic zinc powder, metallic zinc flakes or aluminum flakes; wherein said metal part is a wire spring or a wire clip; and wherein the alkaline solution comprises sodium hydroxide in an amount of 0.1 to 20 wt. % and an accelerator whose main component is sodium meta-silicate; wherein said substrate is washed with water, thereby removing said alkaline aqueous solution, which is adhered after said degreasing treatment.