A round steel chain has chain links articulated to one another, wherein the individual chain links each have opposite chain bends, which are connected to one another by chain legs. At least every second chain link is designed as a flat link, wherein the chain legs of the flat link are flattened at the edges in the cross-section of the chain legs and have a leg width greater than the diameter of the chain bends, such that the areas of the chain legs extending beyond the diameter to the leg width form lateral bulges, which extend up to the chain bends or into the chain bends, and chain bends have thickened sections arranged on the longitudinal outer surfaces of the chain bends.