TIRE REINFORCING STEEL CORD AND TIRE

摘要

A (1 x n)-structure tire reinforcing steel cord which is installed by being wound at opposite side edges of the belt portion of the tire, and formed by twisting 4 to 7 strands each having a wire size of 0.20-0.45 mm, the cord having a spiral/planar waveform permanency, an elongation factor being 1.2-2.0% under a tensile load of 50 N in a tensile test based on JIS B 7721, a tensile load ranging from 50 to 250 N when the cord is linearized. The cord elongates properly by following up the expansion of the tire at tire building, and, after built, has a small elongation characteristic to thereby restrict a radial expansion caused by the high-speed continuous rotation of the tire.