<p>Hard machining is increasingly establishing itself within the industrial manufacturing sector as a highly competitive alternative to grinding. However, research in this area remains limited, particularly concerning milling operations, which require further investigation. This is especially true when it comes to optimizing the balance between quality and productivity of milled parts, a challenge that continues to face industry today. In this study, the aim is to assess quality and productivity performances by examining the relationship between a wear of (TiN + Al₂O₃ + Ti(C, N)) coated carbide tool and surface roughness during dry vertical milling of three hardened tool steels: AISI 52100 (62 HRC), AISI D3 (64 HRC), and AISI 1045 (56 HRC). The cutting parameter regime was held constant to eliminate the influence of cutting vibration variations on the machining technological parameters. First, tool wear and the milled surface roughness over cutting time of the hardened steels were investigated. Subsequently, the correlation between these two responses was analyzed, and the results were converted into mathematical models. The main finding of this analysis is that, beyond the influence of workpiece hardness, the material grade also affects both technological parameters: tool wear and machined surface roughness. Furthermore, online control of these parameters is achievable under certain conditions.</p>