To evaluate the new designed cutting tools for high-efficiency milling of the hardened die steel SKD11,surface integrities of millers with different geometric structures are analyzed, considering the surface roughness, micrograph of chips, surface microhardness, residual stress and metallurgical texture of the surface layer. The in fluences of geometric characteristics of different cutting tools and their wear characteristics on the surface integrity are studied. Results show that the milling tool with rake angle; 5 of the hardened diesteel. The generation of saw-tooth chips is depressed when a reasonable positive rake angle is selected. And the compressive residual stress is induced on the machined surface in milling the hardened die steel. The occurrence of surface softening is postponed by increasing the clearance angle and reducing the tool flank wear.
