RADIUS END MILL, AND CUTTING METHOD

摘要

[Problem] To ensure obtaining highly accurate finishing surface roughness on a work material simultaneous with ensuring highly efficient cutting work. [Solution] The present invention includes a plurality of end cutting edges 3 arrayed around a central axis O and a plurality of arc-shaped radius end cutting edges 6 continuous with the end cutting edges 3 on an outer peripheral side in a radial direction. The end cutting edge 3 is divided into an inner peripheral side end cutting edge 4 and an outer peripheral side end cutting edge 5 in a radial direction. A lowest point Pb of the radius end cutting edge 6 during cutting is positioned in a section from a boundary P2 between the outer peripheral side end cutting edge 5 and the radius end cutting edge 6 to a boundary P4 between the radius end cutting edge 6 and the peripheral cutting edge 7. Second surfaces 40 of the plurality of inner peripheral side end cutting edges 4 are coupled at a part close to the central axis O. A region of coupled second surfaces 40 is continuous from a region including the central axis O to outer peripheral sides of respective inner peripheral side end cutting edges 4 in a radial direction in a strip shape. A width of the strip-shaped region gradually enlarges from the central axis O side to an outer peripheral side in a radial direction.