A steel cord containing a core layer and an sheath layer, the core layer containing a plurality of core wires with a number of n and the sheath layer comprises a plurality of sheath wires with a number of m, and the steel cord has a flat cross-section with a major axis and a minor axis, the flat cross-section has a flat ratio being the ratio of the length of the major axis and the length of the minor axis, the flat ratio is more than 1.2, the steel cord has a breaking load being BL.sub.cord, the core wires and the sheath wires have a sum breaking load being Sum BL.sub.wires when the core wires and the sheath wires are un-twisted from the steel cord, BL.sub.cord and Sum BL.sub.wires satisfies the following formula: BL.sub.cord/Sum BL.sub.wires>96%. The steel cord has higher breaking load.

A tire (1) for an agricultural vehicle, having a crown reinforcement (3), with at least two crown layers (31, 32), each having metal reinforcers which are coated in an elastomer material. Any metal reinforcer of a crown layer (31, 32) has a law, known as a bi-modulus law, governing its elastic behaviour under tension, comprising a first portion having a first extension modulus MG1 at most equal to 30 GPa, and a second portion having a second extension modulus MG2 at least equal to 2 times the first extension modulus MG1, and any metal reinforcer of a crown layer (31, 32) has a law governing its behaviour under compression that is characterized by a critical buckling strain EU at least equal to 3%.

To provide a pneumatic tire excellent in steering stability and durability at high-speed driving, it is provided a pneumatic tire having a tread portion and a belt layer, wherein the tread portion is arranged on the outer side of the belt layer in the tire radial direction, the reinforcing cord in the belt layer is composed of cords made of monofilaments in which 50/5 cm or more of the monofilaments are arranged in the tire width direction in the tire radial cross section of the belt layer, and the maximum load capacity of the tire WL (kg) and the weight of the tire WT (kg) satisfy (WT/WL)≤0.0140.

To provide a pneumatic tire in which both low rolling resistance and improvement of noise performance at high-speed driving are sufficiently achieved, it is provided a pneumatic tire having a tread portion and a belt layer, wherein the tread portion is arranged on the outer side of the belt layer in the tire radial direction, the reinforcing cord in the belt layer is composed of cords made of monofilaments in which 50 lines/5 cm or more of the monofilaments are arranged in the tire width direction in the tire radial cross section of the belt layer, and the maximum load capacity of the tire WL (kg) and the weight of the tire WT (kg) satisfy 0.0145≤(WT/WL).

A two-layer multi-strand cord (60) comprises an internal layer (CI) of the cord made up of J>1 internal strands (TI) and an external layer (CE) of the cord made up of L>1 external strands (TE). The cord satisfies the relationship 95≤MC≤180, where MC=(J×MI+L×ME)/(J+L); MI=200×cos.sup.4(α)×[Q×(D1/2).sup.2×cos.sup.4(β)+P×(D2/2).sup.2×cos.sup.4(δ)+N×(D3/2).sup.2×cos.sup.4(γ)]/[Q×(D1/2).sup.2+P×(D2/2).sup.2+N×(D3/2).sup.2]; and ME=200×cos.sup.4(α′)×[Q′×(D1′/2).sup.2×cos.sup.4(β′)+P′×(D2′/2).sup.2×cos.sup.4(δ′)+N′×(D3′/2).sup.2×cos.sup.4(γ′)]/[Q′×(D1′/2).sup.2+P′×(D2/2).sup.2+N′×(D3′/2).sup.2], where D1, D1′, D2, D2′, D3 and D3′ are in mm, α and α′ are the helix angle of each internal and external strand (TI), β and β′ are the helix angle of each internal thread (F1, F1′), δ and δ′ are the helix angle of each intermediate thread (F2, F2′) and γ and γ′ are the helix angle of each external thread (F3, F3′).

In a pneumatic tire, a plurality of belt layers disposed on an outer circumferential side of a carcass layer in a tread portion are formed of steel cords each having a 1×M structure formed of a number of wire strands. The number of wire strands corresponds to one to six wire strands. A tensile modulus of elasticity of the steel cords under 5 N to 50 N load is 130 GPa or more. The steel cords are arranged inclined with respect to a tire circumferential direction to intersect each other in layers of the belt layers. The belt cover layer disposed on an outer circumferential side of the belt layers is formed of organic fiber cords having elongation of 2.0% to 4.0% under 2.0 cN/dtex load. The organic fiber cords are wound helically along the tire circumferential direction.

A cord (50) comprises a single layer (52) of helically wound metal filamentary elements (54). The metal filamentary elements define an internal enclosure (58) of the cord of diameter Dv. Each metal filamentary element (54) has a diameter Df and a helix radius of curvature Rf. With Dv, Df and Rf being expressed in millimetres, the cord satisfies the following relationships: 9≤Rf/Df≤30 and 1.30≤Dv/Df≤2.10.

A pneumatic tire includes a tread portion, a pair of sidewall portions, a pair of bead portions, a carcass extending between the bead portions through the tread portion and the sidewall portions, a belt layer disposed radially outwardly of the carcass, a band layer disposed radially outwardly of the belt layer, and a pair of belt-edge rubbers disposed between the belt layer and the band layer to cover axially outer edges of the belt layer. The band layer includes a full band and a pair of edge bands covering the axially outer edges of the belt layer. The pair of edge bands includes one or more organic fiber cords each having restraining force in a range from 5 to 35 N at radially outward locations of the outer edges of the belt layer.

The present invention provides a tire that uses an elastomer-metal cord composite, which composite is obtained by coating metal cords with an elastomer, each metal cord being composed of a bundle of metal filaments arranged without being twisted, and which composite is capable of highly improving the performance of the tire. The above described tire is one including a belt (105) which includes at least two belt layers (105a) and (105b). In this tire, the belt layers (105a) and (105b) are each obtained by coating metal cords (2) with an elastomer (3), each metal cord (2) being composed of a bundle of a plurality of metal filaments (1) arranged in a row without being twisted; at least one pair of adjacent metal filaments in the metal cord (2) differ in at least one of the amount of shaping and shaping pitch; each of the belt layers (105a) and (105b) has a thickness t1 of more than 0.30 mm and less than 1.00 mm; and the distance g in the tire radial direction between the metal cords (2) in the two adjacent belt layers (105a) and (105b) is 0.10 mm or more and 1.20 mm or less at the center of the tire.

An outermost end of a carcass folded-up portion is located in a tire width direction inside than an end in the tire width direction of the outermost inclined belt layer, in the tire radial direction between a carcass main body portion and the innermost inclined belt layer. A carcass cord in the folded-up portion located on the outermost side of the tire and a belt cord of the outermost inclined belt layer cross each other to be inclined in the same direction in a tire circumferential direction as being from one side toward the other side in the tire width direction, a difference in inclination angle is 30° or less, a width of the outermost inclined belt layer is larger than that of the innermost inclined belt layer, and in-plane rigidity per unit width of the innermost inclined belt layer is higher than that of the outermost inclined belt layer.