The paper presents the results of studies of internal stresses in ion-plasma coating Ti-TiC-DLC. A method based on measuring the deformation of the substrate was used to carry out this research. Plates of 08kp steel were used as a substrate, the geometry of which was chosen based on their further application for droplet erosion testing and determination of stresses arising in the coating under high-speed drop impact. A technique is presented for conducting research on substrates with a geometry that is changed in comparison with the classical configuration used to determine the internal stresses in the coating by the bending method. Bending values were obtained from the surface profiles obtained before and after coating, which were used to calculate stresses by using the Stoney formula. Application of the selected coating leads to the appearance of compressive stresses ranging from 3 to 9 GPa.