A multi-strand cord (50) comprises an internal layer (CI) of the cord made up of K=1 two-layer (C1, C3) internal strand (TI), 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) of the cord made up of L>1 two-layer (C1′, C3′) external strands (TE) wound around the internal layer (CI) of the cord, 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 endurance criterion SL≤40 000 MPa.Math.mm with

[00001]$SL=\max \left(\frac{\Delta {\sigma }_{\mathrm{bending\_CI}}}{\mathrm{Cp}};\frac{\Delta {\sigma }_{\mathrm{bending\_CE}}}{C_r\times \mathrm{Cp}}\right)$

and a size criterion Ec≥0.46 with Ec=Sc/Se.

A cord (50) comprises a single layer (52) made up of N helically wound metal filamentary elements (54) having an outer diameter D, the metal filamentary elements (54) defining 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 this cord (50), D, Dv, Df and Rf being expressed in millimeters: 0.10≤Jr≤0.25, 9≤Rf/Df≤30, and 1.60≤Dv/Df≤3.20, where Jr=N/(π*(D−Df))×(Dh×Sin(π/N)−(Df/Cos(αx π/180))) and α is the helix angle, expressed in degrees, of each metal filamentary element (54).

The method makes it possible to manufacture an assembly (A) comprising a layer (C) of metal filamentary elements (14) wound in a helix. The method comprises a step (100) of supplying a temporary assembly (22) comprising a layer (13) of M′>1 metal filamentary elements (14) and a temporary centre (16), and a step (110) of separating the temporary assembly (22) between a first split assembly (25), a second split assembly (27) and the temporary centre (16). The method comprises a step (140) of reassembling the first split assembly (25) with the second split assembly (27) so as to form the layer (C) of the assembly (A).

A method for manufacturing a straight steel monofilament for the reinforcement of belt ply of a pneumatic tyre, where the arc-height of the straight steel monofilament is less than 30 mm. The steel monofilament is plastically deformed by a twisting along the axis of the steel monofilament on a double-twist apparatus. The plastic twist deformation eliminates the surface stress difference on the steel monofilament and provides a strainght steel monofilament for belt ply reinforcement. This provides a simple solution with existing apparatus to manufacture straight steel monofilament suitable for tire reinforcement with high speed for mass production.

A stranding machine is provided for producing a cord from a plurality of wires, preferably metal wires. The stranding machine has a stranding device for stranding the wires, including at least one rotatably mounted deflecting roller for deflecting the cord and at least one guide device for guiding the cord. The guide device is arranged in such a way that the cord can be guided on a straight line from the guide device to the deflecting roller in such a way that the cord is pressed against a first flank of the deflecting roller. As the cord is deflected by the deflecting roller, the cord moves from the first flank into the roller base of the deflecting roller.

A straightening device for straightening cables includes two rows of rollers, an adjusting device for manually adjusting a distance between the rows of rollers, a measuring device for recording the distance between the rows of rollers, and an indicator device with which deviations of the actual value of the distance between the rows of rollers, determined by the measuring device, from a nominal value is visually indicated. The indicator device has two optical error indicating elements for indicating too high and/or too low an actual value compared with the nominal value of the distance, as well as an optical correct indicating element for indicating that the actual value of the distance corresponds with the nominal value.

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 manipulation rope having an excellent torque transmittability is provided. A manipulation rope 2 is a rope 2 that is advantageously used as a manipulation rope for a medical instrument, and includes a side wire 6 or a side strand which is an outermost layer, the side wire 6 or the side strand having a spiral shape in which a flatness that is an aspect ratio obtained by a major axis being divided by a minor axis is greater than 1.00 and not greater than 1.10. An elongation of the rope at a time when a tensile load that is 1.0% of a breaking load is applied, is preferably not less than 0.04% and preferably not greater than 0.10%.

A method is provided for manufacturing a multistrand cable having a 1N structure and including a single layer of N strands wound in a helix. Each strand includes an internal layer of M internal threads and an external layer of P external threads. The method includes a step of individually assembling each of the N strands, during which, in chronological order, the M internal threads are wound, the P external threads are wound, and the M internal threads and the P external threads are elongated such that a structural elongation associated with the P external threads of each strand is greater than or equal to 0.05%. The method further includes a step of collectively assembling the N strands, during which the N strands are wound to form the cable.

A stranded wire having a plurality of steel wires twisted together includes, in its cross section perpendicular to its longitudinal direction, a central wire as the steel wire, a plurality of first circumferential wires as the steel wires arranged in contact with the central wire to surround an outer periphery side of the central wire, and a plurality of second circumferential wires as the steel wires arranged in contact with the first circumferential wires to surround an outer periphery side of a region where the first circumferential wires are arranged, the second circumferential wires being greater in yield stress than the central wire and the first circumferential wires. The central wire is in surface contact with the first circumferential wires. The first circumferential wires are in surface contact with the second circumferential wires.