To provide a cutting insert and a rotating tool with a replaceable blade edge in which the elongation of a service life of the tool can be expected and manufacturing costs can be reduced.
A rake face 12 is formed at both sides of an insert body facing the outside of a thickness direction thereof to make a pair. A cutting edge 14 is arranged on each side which constitutes an outer periphery of the rake face 12. The cutting edge 14 is provided with a major cutting edge 18A which is arranged at the center of the side and a minor cutting edge 18B which is arranged at one end of the side and extends so as to intersect with a direction at which the major cutting edge 18A extends when viewed from a direction opposing the rake face 12. A connection part 20 in which a cross section orthogonal to the thickness direction is formed in a concave curved shape is arranged at an opposite side of the major cutting edge 18A across the minor cutting edge 18B and adjacent to the minor cutting edge 18B, and is formed at the insert body over an entire thickness direction of the insert body. Each cutting edge 14 one rake face 12 and each cutting edge 14 of the other rake face 12 are symmetric with respect to each other in terms of forward/rearward rotation.
DAIGUJI HISASHI
Tadashi Takahashi
Yasuhiko Murayama
Noriko Yanai