| 摘要 |
PROBLEM TO BE SOLVED: To provide a reamer capable of improving the circularity and surface roughness of a machined hole of a workpiece.SOLUTION: A cutting portion 14 of the reamer 50 is composed of first to fourth cutting blades 26, 28, 42, 46 arranged in the direction of the rotating shaft R of a body 12. The ends of the first to the fourth cutting blades 26, 28, 42, 46 are projected to the radial direction and have chamfer angles θ-θ. The maximum projection amounts L, L, Lof the second to the fourth cutting blades 28, 42, 46 are larger than the maximum projection amounts L, L, Lof the first to the third cutting blades 26, 28, 42 adjacent to the tip end side 12a. Furthermore, the chamfer angles θ, θ, θof the second to the fourth cutting blades 28, 42, 46 are smaller than the chamfer angles θ, θ, θof the first to the third cutting blades 26, 28, 42 adjacent to the tip end side 12a. |
