In the PhD thesis "Precision of Stainless Steel Turning Process Depending on Al2O3 Nano-Coated Cutting Tool Wear" a method for determining the roughness of a turned surface for hard-to-machine materials has been developed using increased processing parameters, the application of a turning process without cooling emulsion, using new cutting tools, and the cutting process has been investigated. Studying the chip formation process and the result of cutting tool wear using other manufacturer produced tools. A review of the known literature was carried out and research directions were defined. The results of material turning of two groups of stainless steel structures are reviewed. Several mathematical models of the turning process have been developed for predicting surface roughness using regression analysis. The influence of material alloying elements on the chip formation process was studied. The accuracy of the regression prediction models has been evaluated and an experimental model test has been performed. Finite element method modeling of the turning process has been represented and the obtained data, which could not be recieved before with the help of a practical experiment, have been obtained. The thesis contains 130 pages of text, 66 images, 17 tables and 100 information sources.