STEEL CODE FOR REINFORCING TIRE AND PNEUMATIC RADIAL TIRE USING THE SAME

摘要

A steel cord for tire reinforcement and a pneumatic radial tire using the same are provided to improve rubber penetration while preventing lowering of the productivity and an increase of cost by removing an additional twist process. A steel cord is formed of a first layer core(1) formed of one filament(1a), a second layer core(2) formed of three filaments(2a), and a third layer core(3) formed of 7 to 8 filaments(3a). The filament of the first layer core is formed in a straight line or two-dimensional waveform. The second layer core and the third layer core are formed in shape of covering the first layer core in the same twist direction and the same twist period.