The invention provides a steel cord with a construction of n1, n is the number of the steel filaments of the steel cord, the steel cord has an elongation at 2.5N-50N of less than 1.2% and a twist pitch of greater than 16 mm, each of the steel filaments has a form of helical wave with a wave length L expressed in mm and a wave height H expressed in mm when being unravelled from said steel cord, L is greater than 16 mm, each of the steel filaments has a space volume Vs satisfying that, Vs=LH.sup.2/4, and Vs>20 mm.sup.3. The invention steel cord is beneficial for the stress distribution.

The invention relates to a metallic reinforcing cord (10) for tyres for vehicle wheels, comprising from two to ten metallic wires (11) twisted together with a twisting pitch (P) and each having a predetermined diameter. In at least some cross sections of the metallic reinforcing cord (10), at least two of said metallic wires (11) are arranged to a minimum mutual distance greater than, or equal to, 2.5 times the predetermined diameter.

A multi-strand cord (50) comprises an internal layer (CI) of the cord made up of K=1 three-layer (C1, C2, C3) internal strand (TI), with the internal layer (C1) being made up of Q internal metallic threads (F1), the intermediate layer (C2) being made up of M intermediate metallic threads (F2) 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 three-layer (C1, C2, 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), the intermediate layer (C2) being made up of M intermediate metallic threads (F2) and the external layer (C3) being made up of N external metallic threads (F3). The cord (50) has an endurance criterion SL40 000 MPa.Math.mm with $SL=\max \left(\frac{{}_{\mathrm{bending}\_\mathrm{CI}}}{\mathrm{Cp}};\frac{{}_{\mathrm{bending}\_\mathrm{CE}}}{C_r\mathrm{Cp}}\right);$
and a size criterion Ec0.46 with Ec=Sc/Se.