Abstract: A minor cutting edge has a first minor cutting edge and a second minor cutting edge that extends inward of the insert in a direction of an insert short side face axial line, as the second minor cutting edge extends from the first minor cutting edge in a direction of an insert major face axial line. A flank face of the second minor cutting edge is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from the second minor cutting edge in the direction of an insert long side face axial line, and is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from a major face adjacent to the flank face in the direction of the insert major face axial line.

Abstract: A minor cutting edge has a first minor cutting edge and a second minor cutting edge that extends inward of the insert in a direction of an insert short side face axial line, as the second minor cutting edge extends from the first minor cutting edge in a direction of an insert major face axial line. A flank face of the second minor cutting edge is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from the second minor cutting edge in the direction of an insert long side face axial line, and is inclined outward of the insert in the direction of the insert short side face axial line, as the flank face extends from a major face adjacent to the flank face in the direction of the insert major face axial line.

Abstract: The present invention relates to a clamp mechanism which prevents a tip body from being greatly cut out by a fitting hole to secure strength of a tip without complicating the shape of a head portion of a clamp member or a fitting hole of a tip body. There is provided a clamp mechanism of a tip for pressing the tip, in which a fitting hole is formed through a tip body, by the use of a clamp member having a shaft portion inserted into the fitting hole and a head portion with an outer diameter equal to or larger than that of the shaft portion and thus clamping the tip to a tip fitting seat. In the clamp member, a section, which is perpendicular to the central axis line, of the back surface of the head portion has a circle shape centered at the central axis line.

Abstract: The present invention relates to a clamp mechanism which prevents a tip body from being greatly cut out by a fitting hole to secure strength of a tip without complicating the shape of a head portion of a clamp member or a fitting hole of a tip body. There is provided a clamp mechanism of a tip for pressing the tip, in which a fitting hole is formed through a tip body, by the use of a clamp member having a shaft portion inserted into the fitting hole and a head portion with an outer diameter equal to or larger than that of the shaft portion and thus clamping the tip to a tip fitting seat. In the clamp member, a section, which is perpendicular to the central axis line, of the back surface of the head portion has a circle shape centered at the central axis line.