Purpose. Research on surface roughness in turning of traction motor shaft of electric vehicles, depending on the measure of the main cutting edge angle and roundedoff radius of the cutter. Analysis of the impact of vitrified aluminum oxide disk characteris tics on the surface profile after wheel dressing.Methodology. The research was based on existing empirical dependencies that describe the profile of the workpiece surface being machined during turning and grinding. In this case, probabilitytheoretical methods and methods of straightline strip chart recording before and after grinding were used.findings. The irregularity of the surface roughness that occurs after turning of the traction motor shaft of electric vehicles has a significant impact on the choice of geometric parameters of the cutting tool. Most often, roughness is considered as a determin istic set of irregularities of the same size and shape. There are dependencies built from the analysis of the kinematics of the treat ment process and the shape of the tool cutting part. It is advisable to consider the profile of the roughness of treated surface of the part as the sum of all random deviations superimposed on an ideal geometrically calculated profile. In this case, the roughness profile will have a probabilistic character, which was formed as a result of complex stochastic processes that occur during machin ing. Depending on the physical phenomena that accompany the treatment process of the material, the levels of the random com ponent should be adjusted depending on the cutting speed. originality. For the first time, a composite model of surface roughness is considered taking into account the influence of a random component on the geometric parameters of the cutting tool. Impact analysis of the vitrified aluminum oxide disk's char acteristics parameters on the surface profile after dressing the cutting wheel face was conducted.Practical value. The assignments of cutting conditions, taking into account the rational parameters of the main cutting edge angle and apex spherical radius of a cutter will ensure the necessary surface quality after machining motor shaft of electric vehicles and their collectorandbrush assembly units, which will significantly affect the overall efficiency of the electromechanical system of the vehicle. Regularities of forming and describing the relief of a cutting wheel face will make it possible to clarify the number of active gains in the wheelworkpiece contact, the thickness of the cut by individual grains and the components of the cutting force during grinding, which will lead to an increase in the quality of processing the traction motor shaft of an electric vehicle.