This study deals with the characteristics of end-milling the hardened steels (SKD11 and SKD61: HRC53). The experiment under various cutting speeds was done in order to estimate the relationship between the cutting distance and the cutting speed. The cutting forces and the chip temperature were measured in the experiment. The hardness of the chip was also researched after cutting. The tooth form of the used tool and the cutting fluid were varied to estimate the deposition of the materials. Furthermore, the carbide including the chip was observed by AFM and the microscope. As a result, it is clear that the carbide included in SKD11 makes it difficult to end-mill comparing SKD11 and SKD61.
