Radial tire for heavy load and having 80% or lower aspect ratio

A radial tire for a heavy load having an aspect ratio of 80% or less, mountable to a standard 15.degree. tapered rim, having a pair of tire beads, each of the tire beads including a bead core, a cord reinforced carcass ply, the carcass ply being turned up around the bead core in each tire bead from inside to outside to terminate in a radially outer edge thus forming a carcass ply main portion and a pair of carcass ply turnup portions, and a steel cord reinforcing filler which has a portion which extends from the bead core both axially and radially outward thereof to terminate in a radially outer edge, and satisfying the following relationships for each of the tire beads:

• 7.35<(W.sub.1 /D).ltoreq.9.85 wherein W.sub.1 is a thickness of a side wall, along a line perpendicular to the carcass ply main portion from the outer surface thereof to the radially higher one of either the outer edge of the carcass ply or the outer edge of the steel reinforcing filler, and D is the diameter of each cord of the radially higher carcass ply or reinforcing filler and, when the tire is mounted on the rim and inflated to the standard internal pressure, N/H=0.13 to 0.21, wherein N is the radial height of the rim flange to the radially higher outer edge of either the carcass ply or the reinforcing filler and H is the sectional height of the tire.