"Iron" is an ancient measurement used for the thickness of leather. One iron measures 1/48 " (or approximately 1/2 mm.) The 7 iron leather sole will be quite thin (obviously intended for casual summer shoes). The standard thickness for leather soles is 11 - 12 iron (5.5 - 6 mm).Sometimes you see in shoe catalogues the thickness of the sole edge got measured in iron. That is the combination of welt, middle sole (if used) and outer sole.
5/24/14 at 4:17am