| 摘要 |
This invention provides a pneumatic tire having its weight reduced without degrading the durability of bead portions. Provided is a pneumatic tire comprising, as a framework, at least one carcass ply comprising a steel cord covered with rubber. Letting d (mm) be the cord diameter of the steel cord and T (MPa) be the tensile strength of a steel filament forming the steel cord, the following relation is satisfied: a 1 T ˆ’ b 1 > d > a 2 T + b 2 (where a 1 is 3.65 × 10 -4 mm/MPa, b 1 is 0.42 mm, a 2 is -8.00 × 10 -5 mm/MPa, and b 2 is 0.78 mm), and the tensile strength T of the steel filament is 3000 MPa (exclusive) to 4000 MPa (exclusive) and the number of hits E under a bead core of the steel cord in the carcass ply is 12 hits/25 mm (exclusive) to 38 hits/25 mm (exclusive). |
