Patent ID: 7293945

Claim:
A non-rotary cutting tool which is to be moved relative to a workpiece in a predetermined direction for cutting the workpiece, comprising: a generally cylindrical shank portion; and a generally semi-cylindrical body portion which is coaxial with said cylindrical shank portion and which is constituted by a rake face and an outer circumferential surface, said rake face having a width smaller than a diameter of said cylindrical shank portion; wherein said semi-cylindrical body portion has a cutting edge which is configured by a side cutting edge portion and an end cutting edge portion which are provided by an edge of said rake face and are covered with a diamond coating; and wherein said semi-cylindrical body portion has a half-moon shape in cross section where a curved line portion of said half-moon shape is configured by the outer circumferential surface and a single straight line portion of said half-moon shape is configured by the rake face, and a rake angle of said side cutting edge portion and a rake angle of said end cutting edge portion are respectively 0° when cutting the workpiece where the rake angle is an angle between the rake face and a tool reference plane where the tool reference plane is a plane perpendicular to said predetermined relative moving direction; and wherein said side cutting edge portion and said end cutting edge portion intersect perpendicularly with each other, and wherein said cutting tool cuts the workpiece while being kept unrotated.