| 摘要 |
PURPOSE: To obtain a steel cord improved in fatigue resistance and having a compact twist structure. CONSTITUTION: The steel cord comprises element wires whose diameters are 0.15-0.25mm, respectively, and have a compact twist structure. Therein, the central part of the steel cord comprises one-three of the element wires, and six or more of the element wires are twisted on the central part in the same direction and at the same twisting pitch as those of the element wire group of the central part. When the steel cord is bent so as to give a curvature radius of inequality: d/(17×10<-3> ), wherein (d) is the diameter (mm) of the element wire in the outermost layer, the maximum movement distance of the element wire in the outermost layer is <=(-545.4d+145.4)×10<3>μm in comparison with that in the straight state in the cross section of the steel cord.
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