A pneumatic radial tire is provided that includes belt layers disposed on an outer circumferential side of a carcass layer in a tread portion, and a belt cover layer disposed on an outer circumferential side of the belt layers, the belt cover layer including organic fiber cords helically wound along a tire circumferential direction, the belt layers including steel cords arranged at an incline with respect to the tire circumferential direction in such a manner as to intersect one another between the layers, each of the belt layers having a bending rigidity of 16500 N.Math.mm.sup.2/.sub.50 mm or less per 50 mm width in a direction orthogonal to a longitudinal direction of the steel cords, and the belt cover layer including organic fiber cords having an elongation of 2.0% to 4.0% under a load of 2.0 cN/dtex, the organic fiber cords being helically wound along the tire circumferential direction.

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%.

A reinforced product, which can be used in particular for the reinforcing of a finished rubber article, comprises one or more textile or metallic reinforcing threads, the said thread or threads being covered individually or collectively with a sheath comprising a sheathing composition comprising one or more block copolymers comprising at least one polyamide block and at least one polyolefin block, the sheathed thread or threads being themselves embedded in a rubber composition.

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′).

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 tyre for vehicle wheels comprises a support structure and a tread band arranged in a radially outer position with respect to the support structure. The support structure comprises a plurality of hybrid reinforcing cords (10). Each of the hybrid reinforcing cords (10) has at least two strands (20) twisted together with a predetermined twisting pitch. Each of said at least two strands (20) comprises at least one monofilament textile wire (21) and at least one multifilament textile yarn (22) comprising a plurality of textile filaments (22a). In any cross section of the hybrid reinforcing cord (10), said at least one monofilament textile wire (21) is at least partially embedded in the filaments (22a) of said at least one multifilament textile yarn (22).

A tire includes a carcass ply, a tread disposed radially outward of a crown region of the carcass ply, and a belt structure having an overall axial width substantially equal to a tread width interposed between the tread and the crown region in circumferential surrounding relation to the carcass ply. The belt structure includes a first belt layer and a second belt layer radially adjacent the first belt layer. The first belt layer includes a first reinforced composite with first reinforcement cords embedded in a first rubber matrix. The first reinforcement cords have a construction of 1100/4 dtex with a twist between 150 TPM and 250 TPM and a dipping tension between 100 mN/tex and 200 mN/tex.

A plurality of belt layers 7 are superimposed in a radial direction. The belt layers 7 include a plurality of steel cords 10 arranged in parallel in a row and rubber 11. The steel cords 10 have a 1×4 structure in which four filaments 20 are twisted, and when a center-to-center distance between the steel cords 10 in at least two of the belt layers 7 adjacent in the radial direction is T, and an average diameter of virtual circumscribed circles of the steel cords 10 having the 1×4 structure is D, 1.25≤T/D≤2.25.

In a pneumatic tire provided with a carcass layer and a belt layer, the carcass layer is formed of an organic fiber cord having an elongation at break of 20% to 30%, an elongation in a sidewall portion under a load of 2.0 cN/dtex of 5.5% to 8.0%, and a product A = D × Ec of a fineness based on corrected mass D (unit: dtex/piece) and a count Ec (unit: piece/50 mm) of 1.8 × 10.sup.5 dtex/50 mm to 3.0 × 10.sup.5 dtex/50 mm, and the belt layer is formed of a steel cord having a stress at break of 3300 MPa or more and a product B = S x Eb of a cross-sectional area S (unit: mm.sup.2/piece), and a count Eb (unit: piece/50 mm) is from 6.0 mm.sup.2/50 mm to 7.5 mm.sup.2/50 mm.