Abstract During hot-pressing of the tubes, there are possible anomalies that lower the final quality of the product. Getting to know the causes of these anomalies and the possibilities to avoid them require the thorough knowledge of the technological process, structure, and defects of formed material. There are several options how to eliminate the defects. Combination of metalographic analysis and mathematic modeling process enables to remove the faults without the stoppage of production, all that in short time and for a reasonable price. The article deals with optimization of industry pressing of brass tubes. After pressing, the tubes were wisely cracked at the external surface vertical to the pressing direction. Metalographic analysis proved the existence of cracks in the surface fine-grained area. Cracks trenched to interface of fine-grain – coarse-grain structure. Consequently, using a software product Deform 2D, the mathematic simulation of pressing the thin-walled brass tube has been done. Influences of matrix geometry, friction coefficient, pressing temperature, and pressing speed of the intermediate, effected the simulations that were done. There was closely observed an opportunity to lower the tube temperature while pressing that would lead to preventing cracks. The aim of the project was in getting the optimum combination of pressing parameters that would eliminate the risk of defects. The conclusion involves the changes of parameters suggested, that do not allow to create defects on the surface of pressing tubes.