A hollow stranded wire (2) has a first layers (4) and second layers (6). The second layer is located outside the first layer. The first layer is formed by twisting eight first element wires (8) which are flat wires. The second layer is formed by twisting eight second element wires (10) which are flat wires. A ratio (Ww/Tw) of a width Ww to a thickness Tw of each flat wire is from 2 to 11. A twisting direction of the second element wires is opposite that of the first element wires. A twisting angle of each first element wire is not greater than 85. A twisting angle of each second element wire is not greater than 85. A ratio (D/T) of an average diameter D to a thickness T of the hollow stranded wire is not less than 5 and not greater than 20.

Provided is a steel cord for rubber article reinforcement, which has both the tensile strength in the cord axial direction and the strength in the shear direction at higher levels. A steel cord (10) for rubber article reinforcement includes: a single core strand (11) having a layer-twisted structure; and plural sheath strands (12) each having a layer-twisted structure, and the sheath strands (12) are twisted around the core strand (11). In the sheath strands (12), a ratio between the diameter of a core filament (12a) and the diameter of a sheath filament (12b) is 0.75 to 0.85, and a ratio between the strength of the core filament (12a) and the strength of the sheath filament (12b) is 0.55 to 0.7.

Disclosed are a cable bead and a tire. The cable bead includes a core wire located at the middle position of the bead and at least one layer of outer winding wires wound around the core wire, each layer of outer winding wires being evenly wounded along the circumferential direction of the core wire, where the cross section of the outer winding wires is a flat surface having a major axis and a minor axis; the major axis is perpendicular to the radial direction of the cross section of the bead, and the minor axis is parallel to the radial direction of the cross section of the bead; the outer winding wires are in surface contact with the core wire; and when there are at least two layers of outer winding wires, a line contact is formed between the layers of outer winding wires.

A cord (50) comprises: an internal strand (TI) comprising an internal layer (C1), and an external layer (C3); and L>1 external strands (TE) comprising an internal layer (C1) of Q=1 internal wire (F1), an intermediate layer (C2) of M intermediate wires (F2) wound around the internal layer (C1) with a pitch p2, and an external layer (C3) of N external wires (F3) wound around the intermediate layer (C2) with a pitch p3. The external layer (CE) of the cord is wound around the internal layer (CI) of the cord in a direction of winding of the cord (50). Each external layer (C3, C3) of each internal and external strand (TI, TE) is wound in the same direction of winding that is the opposite to the direction of winding of the cord (50). The external layer (CE) of the cord (50) is desaturated, and 0.36(p3p2)/p30.57.

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).

Hybrid rope (20) comprising a core element (22) containing high modulus fibers surrounded by at least one outer layer (24) containing wirelike metallic members (26). The core element (22) is coated (23) with a thermoplastic polyurethane or a copolyester elastomer, preferably the copolyester elastomer containing soft blocks in the range of 10 to 70 wt %. The coated material (23) on the inner core element (22) is inhibited to be pressed out in-between the wirelike members (26) of the hybrid rope (20) and the hybrid rope (20) has decreased elongation and diameter reduction after being in use.

An embodiment of a wellbore cable comprises a cable core, at least a first armor wire layer comprising a plurality of strength members and surrounding the cable core, and at least a second armor wire layer comprising a plurality of strength members surrounding the first armor wire layer, the second armor wire layer covering a predetermined percentage of the circumference of the first armor wire layer to prevent torque imbalance in the cable.

A linear member for medical use having stretchability and flexibility while maintaining sufficient strength includes: an inner helical body including a plurality of helically wound wires, the inner helical body including a space portion inside, gap portions being provided in an axial direction between each wire; and an outer helical body provided outside of the inner helical body including a plurality of wires helically wound in such a manner as to form a layer along an axis of the helical body and a helical direction of the outer helical body is opposite to that of the inner helical body with gap portions being provided between each of the wires, the outer helical body being disposed to provide a multilayer structure.

A multi-strand cord (50) comprises an internal layer (CI) made up of K=1 internal strand (TI) having two layers (C1, C3), with the internal layer (C1) being made up of Q internal metallic threads (F1) and the external layer (C3) being made up of N external metallic threads (F3), and an external layer (CE) made up of L>1 external strands (TE) having two layers (C1, C3) wound around the internal layer (CI), with the internal layer (C1) being made up of Q internal metallic threads (F1) and the external layer (C3) being made up of N external metallic threads (F3). The cord (50) has an energy-to-break per unit area ES145 N.Math.mm.sup.1 with $ES={.Math.}_{i=1}^{Nc}{F}_{mi}{.Math.}_{i=1}^{Nc}{A}_{ti}/\mathrm{Nc}\mathrm{Cfrag}/D$
where ${.Math.}_{i=1}^{Nc}{F}_{mi}$
is the sum of the forces at break, ${.Math.}_{i=1}^{Nc}{A}_{ti}$
is the sum of the total elongation, Cfrag is the coefficient of weakening, and D is the diameter.