Modern methods of steelmaking and out-of-furnace treatments of steel have made it possible to sharply reduce its content of gases, sulfur, and phosphorus. However, there has been little study of the effect of small concentrations of non-ferrous metals on steel's structure and properties. Lead, tin, bismuth, antimony, zinc, and other nonferrous metals enter steel from the charge, the alloying materials, and the deoxidizers. In most cases, the concentrations of these elements are not determined and are not indicated in the elemental chemical composition of the heat. In order to determine the highest concentrations of impurities of Pb, Sb, Sn, Bi, and Zn that will not significantly affect the quality of finished products made of the different steels produced by the company Azovstal', researchers at the company's laboratory studied the effect of different concentrations of each impurity individually on the quality of an alloy based on steel S355J2G3. Each of the five trial heats was cast into four ingots having different contents of nonferrous metals. The results of the studies showed that intensive cracking, flaking, and scab formation in the experimental steel became noticeable at concentrations of Pb or Bi > = 0.0055%; Sb > = 0.0038%; Sn > = 0.0060%; Zn > = 0.018%.