Annotation: This article describes the method that is designed to determine the properties of steels. The structure of the expert system which designed to determine the nominal values of the properties of steels is developed. The fragment of the steels knowledgebase which contains the set of rules of steels properties is shown. The neural network is developed to refine upon the values of the steels properties. The results of simulations of the developed neural network are shown. The authors note the low standard error of the neural network.