PNEUMATIC RADIAL TIRE FOR HEAVY LOAD

PURPOSE:To prevent the end of the third ply from generating rubber cracks by specifying the extension when the cord of the fourth ply from the carcass side is broken and width of the fourth ply out of the four belt ply arranged between the carcass and a tread. CONSTITUTION:A tire is provided with four belt plies 21 to 24 between a carcass 10 and a tread 30, and each of the plies 21 to 24 is arranged with steel cords in parallel with each other. The cords of the first ply 21 and the second ply 22 are inclined in the same direction in relation to the center line 40 in the circumference of the tire, and the cords of the second ply 22 and the third ply 23 in the directions opposite to each other, and the cords of the third ply 23 and the fourth ply 24 in the same direction respectively. In the constitution mentioned above, the extension of the fourth ply 24 when the cord is broken is set to 5% or more, and the width of the fourth ply 24 is also formed larger than that of the third ply 23. The end of the third ply 23 is coated with the fourth ply 24 for preventing the end from generating rubber cracks.