Abstract: The present invention provides a method which enables a steel wire to be highly strengthened with maintaining good ductility. Specifically, the present invention provides a method comprising: subjecting a high carbon steel wire material having carbon content of 0.85 to 1.10 mass % to a pre-stage drawing process with a predetermined magnitude of drawing, to form an intermediate wire material; subjecting the intermediate wire material formed by the pre-stage drawing process to a patenting treatment in which tensile strength of the wire material is adjusted to a range of 1323 to 1666 MPa; then subjecting the patented steel wire material to a subsequent drawing process including the final drawing.

Abstract: The present invention provides a method which enables a steel wire to be highly strengthened with maintaining good ductility. Specifically, the present invention provides a method comprising: subjecting a high carbon steel wire material having carbon content of 0.85 to 1.10 mass % to a pre-stage drawing process with a predetermined magnitude of drawing, to form an intermediate wire material; subjecting the intermediate wire material formed by the pre-stage drawing process to a patenting treatment in which tensile strength of the wire material is adjusted to a range of 1323 to 1666 MPa; then subjecting the patented steel wire material to a subsequent drawing process including the final drawing.

Abstract: A steel cord for the reinforcement of rubber articles is formed by twisting plural filament wires of a high carbon steel. In this case, the filament wire is drawn from a wire rod so as to satisfy a relationship of T.gtoreq.230-148 logD (wherein D is a diameter of the filament wire and T is a tensile strength of the filament wire) and a difference in tensile strength between a surface layer portion and an internal portion in the filament wire of not more than 80 kgf/mm.sup.2.

Abstract: A composite rubber body is formed by embedding steel cords in rubber and vulcanization-building them. In this case, each of the steel cords is a single steel filament wire or plural twisted steel filament wires obtained by drawing of a wire rod of high carbon steel having a given composition. The filament wires satisfy given relationships between filament diameter and tensile strength before and after the vulcanization and have a retention of loop strength of not less than 55%.