| 摘要 |
<p>The rotary cutting tool is provided with a tool body (11) having a shank portion (11A) and a neck portion (11B), an insert attachment seat (12) formed at the tip of the neck portion (11B), and a cutting insert detachably mounted on the insert attachment seat (12) so as to be coaxial with the axis line of the shank portion (11A). The insert attachment seat (12) is provided with a bottom surface (12A) on which a side surface which serves as a seating surface of a cutting insert is seated and a wall surface (12B) in contact with a peripheral surface of the cutting insert. On the bottom surface (12A), a plurality of recessed grooves (20) which are recessed from the bottom surface to extend in the circumferential direction of the neck portion (11B), with the both ends being opened on an outer peripheral surface of the neck portion (11B), are formed so as to travel around the insert attachment seat (12) around the axis line (O). Each of these recessed grooves (20) extends in such a manner that at least the both ends thereof move radially to the outer peripheral side with respect to the axis line (O) toward the both end sides from a circle (E) which is centered on the axis line (O) in contact with the center between the both ends. The bottom surface (12A) extends between the mutually opposing ends of the recessed grooves (20) adjacent in the circumferential direction.</p> |
