Abstract: A bead core formation apparatus includes a rubber coating device that coats a circumferential surface of a steel wire with rubber, and two cooling rollers around which the rubber-coated wire, which is a steel wire coated with rubber, is wound. The second roller includes a first groove and a second groove around which the rubber-coated wire located at a downstream side of the first groove is wound. The diameter LB of a portion including the second groove is smaller than the diameter LC of a portion including the first groove.

Abstract: A bead core formation apparatus includes a rubber coating device that coats a circumferential surface of a steel wire with rubber, and two cooling rollers around which the rubber-coated wire, which is a steel wire coated with rubber, is wound. The second roller includes a first groove and a second groove around which the rubber-coated wire located at a downstream side of the first groove is wound. The diameter LB of a portion including the second groove is smaller than the diameter LC of a portion including the first groove.

Abstract: A bead wire manufacturing method/apparatus includes a descaling step/device for removing oxide on the surface of a wire rod, a coating liquid adhesion step/device for adhering a coating liquid to the wire rod, wiredrawing steps/devices for performing area reduction workings on the wire rod, and a bluing step/device for bluing the wire rod having been raised to a high temperature through the area reduction workings, in a temperature range of 350° C. to 480° C. Thus, the wire rod having been raised to a high temperature through wiredrawing is blued without being cooled down to effectively utilize the temperature retained therein, so that the method/apparatus is little in energy loss.

Abstract: A tire bead wire and a process for producing a tire bead where a carbon steel wire rod containing carbon in a range of 0.61% or more to 0.65% or less in weight percent and having a diameter in a range of 5.5 mm to 6.5 mm is wiredrawn through a single wiredrawing process to a predetermined final wiredrawing diameter having a true strain in a range of 2.0 to 4.0 and is turned to a pearlite structure in which ferrite and cementite are drawn in parallel with a narrow interval therebetween.