Patent ID: 7726218

Claim:
A clamp mechanism of a throwaway tip for pressing a throwaway tip, the clamp mechanism comprising: a tool body having a tip body; a fitting hole formed through the tip body; a tip fitting seat formed in the tool body; a contact portion of the tip body formed in an opening of the fitting hole; and a clamp member comprising: a shaft portion inserted into the fitting hole; a head portion which passes through the fitting hole, the head portion having an outer diameter equal to or greater than that of the shaft portion and clamping the throwaway tip to the tip fitting seat by allowing the clamp member to advance toward the tip fitting seat in a central axis direction of the shaft portion; and a section of a back surface of the head portion, the section being perpendicular to the central axis direction and having a circle shape centered at the central axis line; wherein a part of the back surface of the head portion comes into contact with the contact portion formed in an opening of the fitting hole when the clamp member is allowed to advance.