Abstract: A steel cord (1) for the reinforcement of rubber articles such as tires includes a core of two to four steel filaments (2) and a layer of steel filaments (3, 4) around the core. All of the filaments have a diameter between 0.15 and 0.40 mm and are twisted in the same direction and at the same pitch. The cord has over a substantial portion of its entire length cross-sections where the accumulated gaps between adjacent layer filaments are at least 0.03 mm. At least one filament of the layer has been preformed differently from the other filaments. The above structure avoids core migration.

Abstract: A steel cord (1) for the reinforcement of elastomers, especially for the reinforcement of breaker layers in a tire, said steel cord comprising two strands of at least two filaments (11, 12) each, said strands being twisted around each other and forming helicoids of a same pitch, the filaments (11) of the first strand having a pitch differing from the pitch of said helicoids and having a value of more than 300 mm, the filaments (12) of the second strand having the same pitch as said helocoids and being twisted in the same sense as said helicoids, all the filaments of both of said strands having a diameter between 0.08 and 0.45 mm, wherein the diameter of the filaments of one of said strands is at least 0.02 mm greater than the diameter of the filaments of the other of said strands. Preferably the diameter of the filaments (12) of said second strand is at least 0.02 mm greater than the diameter of the filaments (11) of said first strand.