Magnetically hard and ferroceramic materials exhibit a high propensity for crack and chip formation during blank production and subsequent grinding, which limits the surface quality and yields of finished parts. This study presents a combined theoretical and experimental investigation into the thermomechanical origins of grinding-induced defects and proposes practical criteria to mitigate them. We develop a mathematical model describing the evolution of thermomechanical stresses and the stress intensity factor around inherited inclusions and microcracks formed during sintering, thermomagnetic treatment (TMP), and rough grinding. The model is validated through experiments on Alnico‑type alloys processed under varying sintering temperatures (800–860 ℃), TMP directions, and grinding regimes. Crack and chip formation intensities were quantified on polished surfaces, establishing functional relationships between blank production parameters, microstructural anisotropy, and defect emergence. Key results include analytical criteria for critical defect sizes that prevent main‐crack propagation and optimized combinations of grinding depth, cooling media, and wheel characteristics that maintain stress intensity below the material’s crack‐resistance coefficient. Applying these guidelines in finishing operations reduced crack and chip rates by 15–20%. These findings offer scientifically grounded methods and practical recommendations for selecting blank production and grinding conditions to enhance surface integrity in magnetically hard and ferroceramic components.