Pneumatic radial tire

A pneumatic tire comprising:

• a pair of bead cores;
• a carcass layer folded around each of the pair of bead cores;
• a plurality of belt layers provided on an outside portion of the carcass layer in a tire radial direction, each of the belt layers including a plurality of single steel wires with an identical wire diameter extending linearly in an identical direction in alignment with each other and embedded in rubber, each of the single steel wires provided with axial torsion;
• a tread portion provided on outside portions in the tire radial direction of the belt layers and provided with circumferential grooves that extend in a tire circumferential direction on a tire surface;
• and
• at least one belt cover layer wound around outside portions in the tire radial direction of the belt layers in at least a region corresponding to an outermost circumferential groove in a tire width direction of the pneumatic radial tire, the number of layers of the belt cover layer in the region being greater than the number of layers of the belt cover layer in a center region in the tire width direction;
• the wire diameters of the single steel wires being 0.28 mm to 0.38 mm;
• an average of intervals of the single steel wires being not less than 0.10 mm;
• and
• an out-of-plane bending stiffness being not less than 6000 N·mm2 per inch of length in the circumferential direction of the tread portion when a force application point is located at the circumferential groove.