Abstract: Provided is an annular bead ring formed from a bead wire that has been subjected to wire drawing, the bead wire having a true strain ? of 2.80 or greater as calculated by ?=ln(d0/d1)2, a tensile strength of 2000 MPa or greater, and a proof stress of 1700 MPa to 1980 MPa, where do is a wire diameter (mm) of the bead wire before wire drawing and di is a wire diameter (mm) of the bead wire after wire drawing.

Abstract: A pneumatic radial tire includes: a pair of bead portions; a pair of side wall portions; and a tread portion in which a carcass layer is mounted between the pair of bead portions, and a belt layer that includes a plurality of monofilament steel wires laid in parallel and embedded in rubber is disposed between the pair of side wall portions on an outer circumferential side in the tread portion. The wire strand diameter of the monofilament steel wires is from 0.30 mm to 0.40 mm, each of the monofilament steel wires is twisted around their axial direction with a wire surface twisting angle of 1° to 15° with respect to the axial direction of the monofilament steel wires, and the surface residual stress of the monofilament steel wires is 0 MPa or less.

Abstract: The pneumatic tire according to the present technology has a reinforcing layer in which a plurality of steel cords is laid in parallel and embedded in rubber, wherein each steel cord is configured from a plurality of wires twisted together, the wire diameter is from 0.15 mm to 0.40 mm, each wire is configured from a core and a plating layer formed on the periphery of the core, the core is made from carbon steel with a carbon content of from 0.60 mass % to 0.75 mass %, the average thickness of the plating layer is from 0.23 ?m to 0.33 ?m, and the strength of the steel cord is from 3000 MPA to 3500 MPa.