When polycrystalline cubic boron nitride (PCBN) cutting tools machine hardened steel GCr15, the effects of the chamfered edge parameters (including chamfer width and chamfer angle) on the cutting force, cutting temperature and saw-tooth chips morphology were investigated respectively. The results indicate that the main cutting force, radial force and cutting temperature increase gradually with the increment of chamfer width, but the chamfer width has less effect on the serrated saw-tooth chips. It is shown that the cutting force, radial force and cutting temperature increase with the enlargement of chamfer angle, and the radial force increases more significantly. As the chamfer angle is 20°, the chips has the lowest serration.