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 steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.

The invention provides a steel cord, the steel cord comprises two or more steel filaments, at least one of the steel filaments has a twist pitch of 6 mm to 40 mm, each of the steel filaments has a tip rise of less than 5 mm with a gauge length of 200 mm after being unravelled out of the steel cord. The invention steel cord has an improved straightness with reduced steel filament fracture risk.

A steel cord, a production method thereof, and a tire are provided. The steel cord is formed by twisting multiple steel wires, at least one of the steel wires is deformable to allow the cord to have an irregular surface morphology, and the irregular surface morphology is located at one or two symmetrical identical positions in an axial direction of the cord, such that a cross-section of the cord has a long axis and a short axis unequal to the long axis. The irregular surface morphology of the cord designed in the application is located at identical positions in the axial direction of the cord and destroys the uniform support state of steel wires in the circumferential direction of the cord, and it is difficult for the cord to maintain its original circular cross-section form in the subsequent stress relieving process, such that a flat cord can be produced.