| 摘要 |
Providing a radius endmill having a construction which leads to reduction in cutting resistance acting on the tool and the consequent improvement in durability of the tool, which permits each of produced chips to have reduced thickness and weight and accordingly facilitating smooth evacuation of the produced chips, thereby making it possible to prevent breakage of the tool and defectiveness of the machined surface which could be caused if the tool and the machined surface were interfered by the produced chips. The radius endmill has a substantially cylindrical shape as a whole, and includes the spiral-shaped peripheral cutting edges 2 formed in the outer peripheral portion 1, the bottom cutting edges 4 formed in the axial end portion 3, and the rounded corner cutting edges 5 formed in the corner portion at which the peripheral cutting edges 2 are connected to the bottom cutting edges 4, wherein the ridge line 6 of each bottom cutting edge 4 extends from the center O of the axial end portion 3 to the free end X at which the ridge line 6 is connected to the ridge line 7 of the corresponding rounded corner cutting edge 5, and is constituted by the circle of curvature having the convex circular arc shape as seen in the plan view. |
