The pneumatic tire which uses the bead core and its bead core for the pneumatic tire

摘要

A bead core (10) for a pneumatic tire is composed of an annular bead wire bundle (13) which is formed by winding a single bead wire (12) by a plurality of turns. A step reduction member (20) is provided at a stepped portion (17) caused by a winding beginning end (15) of the bead wire (12). Also, a pneumatic tire (1) is provided with a pair of bead portions (4) in which the bead cores (10) for a pneumatic tire having the step reduction members (20) are arranged and a carcass (5) which extends between the pair of bead portions (4, 4) and is folded back around the respective bead cores (10) at both ends.