The object of the invention is a rolled, forged or extruded aluminum alloy product more than 12 mm thick, heat treated by solutionizing, quenching and artificial aging, with a microstructure characterized by the following parameters: the fraction of recrystallized grains measured between one-quarter thickness and mid-thickness of the final wrought product is smaller than 35% by volume; the characteristic intercept distance between recrystallized areas is greater than 250 .mu.m, preferably greater than 300 .mu.m and most preferably greater than 350 .mu.m.