Patent ID: 8117818

Claim:
A steel cord comprises a multi-twist structure in which N (N=2 to 8) strands are twisted, each strand being formed by twisting a plurality of element wires and having a substantially elliptical cross-section, wherein d 1 /d 2 >1.08 is satisfied where the major diameter of the strand is represented by d 1 and the minor diameter is represented by d 2 , and ε c defined by the following equation: ε c =√{square root over ( )}(− b/ 2+√{square root over ( )}( b 2 /4 −c ))−1 (in the equation, b represents −1+π 2 (−4R 2 +d 2 )/P 2 , c represents π 2 d 2 k(4π 2 R 2 +P 2 )/P 4 , R represents (D−d)/2, k represents tan 2 (π/2−π/N), and d represents (d 1 +d 2 )/2) satisfies ε c >0.005, where the diameter of a circle circumscribing the cord is represented by D (mm) and the twist pitch of the cord is represented by P (mm).