We study the scattering of electromagnetic waves from metallic self-affine surfaces, and review earlier approximative results for the angular distribution of the scattered light (the mean differential reflection coefficient). Furthermore, experimental scattering data for industrial cold-rolled aluminium surfaces that show self-affine scaling invariance are presented. Comparison between these experimental data and approximative analytic and rigorous numerical simulation results shows very good agreement over the dominating angular interval where most of the scattered power is distributed. The excellent quality of this agreement suggests that light scattering can be used as a cheap, robust and versatile (inverse scattering) tool for characterizing self-affine metallic surfaces, i.e. used to estimate roughness exponents as well as topothesies and the related slope parameters.