| 摘要 |
PROBLEM TO BE SOLVED: To provide a steel cord for reinforcing a rubber article which does not cause a treat to curl, and to provide a pneumatic radial tire obtained by using the same.SOLUTION: The steel cord for reinforcing a rubber article is composed of a core including M pieces of core filaments 1 and N pieces of sheath filaments 2 twisted around the core. When a diameter of the core filament 1 is denoted by d1 and a diameter of the sheath filament 2 is denoted by d2, d1>d2 is satisfied, when an average preforming ratio of the core filament 1 is denoted by H1 and an average preforming ratio of the sheath filament 2 is denoted by H2, H1<H2 is satisfied, and when a carbon content of the core filament 1 is denoted by C1 (mass%) and a carbon content of the sheath filament 2 is denoted by C2 (mass%), C1>C2 is satisfied. |
