| 摘要 |
PROBLEM TO BE SOLVED: To suppress the elongation and clogging of chips in a variety of cut-in conditions and feed conditions, to favorably maintain chip processing performance, and to secure machined surface accuracy.SOLUTION: On a surface 3A of an insert main body, there are arranged a breaker groove wall 20a, a first breaker erecting wall 21a, a first breaker apex face 21b and a second breaker erecting wall 22a in this order while being oriented to the inside of an insert radial direction from a corner blade 9, and the first breaker apex face 21b is retracted toward a rear surface side of the surface 3A in an insert axial line direction rather than the corner blade 9. A distance a in an insert radial direction from the corner blade 9 up to a first boundary line 31 which is located in a boundary between the breaker groove wall 20a and the first breaker erecting wall 21a is set to 0.3 mm or shorter, and a distance b in the insert axial line direction from the first boundary line 31 up to the first breaker apex face 21b is set to 0.06 mm or longer.SELECTED DRAWING: Figure 6 |
