A steel cord and a manufacturing process are disclosed. The steel cord includes a steel core wire located in the center and having a diameter of d; and M sheath-layer steel wires arranged around the steel core wire in the center, tangent to the steel core wire, and having a diameter of d1, at least two gaps L existing between the M sheath-layer steel wires, where M is 4; d, d1, and L satisfy the following relationship: 0.420<(d/d1)<0.800, d1 is between 0.20 mm and 0.44 mm, and L0.0008 mm. The steel cord of the present invention may allow rubber to be fully penetrated into the gaps, thereby reducing air content in the steel cord, avoiding point contact friction between the layers of steel wires due to insufficient rubber penetration, and further solving the problem of failure of the bearing capacity of the steel cord due to abrasion.

A steel cord for reinforcing a breaker or belt ply in a rubber tire having a core group and a sheath group. The core group consists of two to four core steel filaments with a first diameter dc and the sheath group consists of one to six sheath steel filaments with a second diameter ds. The ratio dc/ds of the first diameter dc to the second diameter ds ranges from 1.10 to 1.70. The two core steel filaments are untwisted or have a twisting step greater than 300 mm. The sheath group is twisted around the core group with a cord twisting step in a cord twisting direction. The ratio of the difference in residual torsions of the core group and the sheath group to the difference in saturation level between the core group and the sheath group ranges from 0.10 to 0.65, preferably from 0.10 to 0.60.

Provided is a method for manufacturing a tire using a steel cord which can be manufactured without reducing productivity and can prevent propagation of moisture inside. The method for manufacturing a tire includes a vulcanization step of vulcanizing a green tire provided with a belt having at least one belt layer, in which the belt layer includes a steel cord 10 formed by twisting a steel filament 2 together with a resin filament 1 having a softening point of 125 C. or lower, and the resin filament 1 includes at least an ionomer.

Provided is a rubber-cord composite, a tire reinforcing member including the composite, and a tire including the reinforcing member. The rubber-cord composite includes a reinforcing cord, and the composite forms a spiral cord layer in the tire reinforcing member. The twist coefficient of the reinforcing cord is greater than 0.3.

Disclosed herein are vehicle tires including a carcass with at least one body ply, a tread disposed radially outward of the carcass, and a belt component comprising a steel cord-containing ply positioned radially between the tread and the carcass. The steel cord-containing ply comprises rubber reinforced with steel warp cords having a specified diameter and EASL. Also disclosed is a vehicle tire containing two belt components comprising a steel cord-containing ply, each belt component positioned radially between the tread and the carcass.

Provided is a steel cord for reinforcing rubber articles, which can prevent a reduction in the strength of the steel cord caused by twisting steel filaments, and a tire and a crawler using the steel cord. Provided is a steel cord 1 for reinforcing rubber articles formed by twisting a plurality of sheath strands 3 are twisted around a core strand 2, and the core strand 2 comprises: a core composed of two core filaments 2a aligned in parallel without being twisted; and at least one sheath composed of a plurality of sheath filaments 2b twisted around the core, and a diameter dc of the core filament 2a and a diameter ds of the sheath filament 2b satisfy the following expression (1):

dc<ds (1)

and the tensile strength T (MPa) of the core filament 2a satisfies the relationship represented by the following expression (2):

T<365017000(dc0.15).sup.2 (2).

A cord of a band of a tire has a single-stranded structure in which steel filaments are stranded, and the number of the filaments is not less than three and not greater than six. In a cross-section of the cord, when represents a diameter of a smallest circle that surrounds cross-sections of the filaments, and represents a diameter of each filament, a gap is formed between the filaments such that the diameter is not less than three times the diameter and not greater than six times the diameter in the case of the number of the filaments being three or four. An initial elongation of the cord is not less than 0.1% and not greater than 1.5%.

A cord rubberized in situ (C). Internal layer of the cord (CT1) comprises N1 internal thread(s). External layer of the cord (CT3) comprises N3 external threads wound helically around the internal layer of the cord. Rubber composition (20) is positioned between the internal layer of the cord and the external layer of the cord, and comprises a compound of formula (I) or a salt of this compound: ##STR00001##
in which: each R1, R2 and R3 group represents, independently of one another, an alkylene, arylene, arylalkylene, alkylarylene or cycloalkylene group, each X.sub.1 and X.sub.2 group represents, independently of each other, COOH, CONHOH, SOOH, PO(OR)(R) or PO(OR)(OR) with R and R representing, independently of each other, hydrogen or an alkyl group, and X.sub.3 comprises at least one COOH, CONHOH, SOOH, PO(OR)(R) or PO(OR)(OR) group with R and R representing, independently of each other, hydrogen or an alkyl group.

Provided are: a tire steel cord having not only excellent cutting resistance and corrosion resistance but also excellent processability in plant; and a pneumatic tire including the same. The tire steel cord has a layer-twisted structure including: a core 11 composed of two core filaments 1; and a sheath 12 composed of eight sheath filaments 2 that are twisted together around the core 11, in which tire steel cord the two core filaments 1 constituting the core 11 are twisted together, the twisting direction of the core filaments 1 and that of the sheath filaments 2 are different, and a diameter (Dc) of the core filaments 1 and a diameter (Ds) of the sheath filaments 2 satisfy a relationship represented by the following Equation (1):

0.90Ds/Dc1.10(1).

Provided is a pneumatic tire in which the crack propagation resistance of crossing belt layers is improved without deterioration of the cutting resistance and the irregular wear resistance. The pneumatic tire includes a belt composed of at least three belt layers 103 on the tire radial-direction outer side of a carcass 102, the at least three belt layers 103 including two crossing belt layers that are inclined in the opposite directions across the tire equatorial plane. In this pneumatic tire, a reinforcing material of crossing belt layers 103a and 103b is a steel cord which has a layer-twisted structure including a core composed of two core filaments and a sheath composed of eight sheath filaments that are twisted together around the core, and a steel cord amount in the crossing belt layers 103a and 103b, which is represented by the following Equation (1), is 23 to 49: Steel cord diameter (mm)Steel cord end count (steel cords/50 mm) (1).