Our study takes a unique approach by considering the joint influence of defect sizes, orientations, placements, and distributions of processed materials, which are usually determined randomly. This statistical nature of crack formation on treated surfaces, manifested by a thermal fluctuation mechanism of destruction, is a critical factor in our analysis of crack formation phenomena on processed surfaces during finishing operations. This approach is relevant for selecting technological conditions for defect-free processing of products and has significant practical implications for the manufacturing industry. Our research aims to develop a probabilistic-statistical model of crack formation on the grinding surfaces of parts made of materials prone to this type of defect. We strive to propose probabilistic criteria for the appearance of grinding cracks and the selection of technological conditions for their elimination based on them. The statistical characteristics of cracks are calculated by thermal influence on the treated surface. Our study shows that the increase in material homogeneity increases the value of the thermal current, corresponding to the fixed probability that cracks occur on the treated surface. We recommend using the statistical characteristics obtained from limiting heat flow with a large number of crack-like defects in the surface layer of the material being processed as a criterion for the crack formation process during grinding to select technological parameters for defect-free processing.