CUTTING INSERT AND ROTARY TOOL WITH A REPLACEABLE BLADE EDGE

摘要

A rake face (12) is formed on the both sides of an insert main body facing outside in the thickness direction thereof to make a pair, a cutting edge (14) is arranged respectively 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 and which is arranged on the opposite side of the major cutting edge (18A) across the minor cutting edge (18B) and adjacent to the minor cutting edge (18B) is formed on the insert main body over the entire thickness direction of the insert main body. Of the pair of rake faces (12), each cutting edge (14) on an outer periphery of a first rake face (12A) and each cutting edge (14) on an outer periphery of a second rake face (12B) have rotation symmetry with each other.