Rotary cutting tool

A reamer comprising a tool body and a cutting edge tip provided at the tool body, wherein

• at least one first groove is provided in a rake face of the cutting edge tip, wherein the rake face is defined by the tool body and the cutting edge tip,
• the first groove has a portion inclined with respect to a rotation axis,
• a front end of the first groove is disposed on a front cutting edge or a corner chamfering cutting edge, the front end of the first groove being configured to cut off a chip,
• a rear end of the first groove is provided on an inner side with respect to an outer peripheral cutting edge, and an irregularity of the outer peripheral cutting edge at a ridgeline portion thereof in a direction parallel to the rake face is 30 μm or less, and
• the first groove is inclined toward an inner peripheral side in a direction from the front end toward the rear end of the first groove, and a wall surface intersecting an extending direction of each of the rake face and the first groove is provided in a vicinity of the rear end of the first groove,
• wherein the first groove is in a form of a straight line, and has an angle of 5° or more and 85° or less with respect to the rotation axis,
• wherein a plurality of the first grooves are provided, and an interval between the plurality of first grooves is 0.1 mm or more and 2 mm or less,
• wherein a depth of the first groove is 0.01 mm or more and 0.8 mm or less, and
• wherein a width of the first groove is 0.01 mm or more and 0.5 mm or less,
• wherein the irregularity results from
• chipping caused at the ridgeline portion of the outer peripheral cutting edge,
• detachment in a vicinity of a ridgeline on the rake face side, or
• the first or second groove being formed to extend to the outer peripheral cutting edge portion.