Patent ID: 8025465

Claim:
A cutting tool, comprising: a first cutting insert comprising a first side surface connecting a first upper surface and a second lower surface, a first cutting edge located at an intersection of the first upper surface and the first side surface, and a first groove portion which is located on the first side surface, reaches the first upper surface, and divides the first cutting edge; a second cutting insert comprising a second side surface connecting a second upper surface and a second lower surface, a second cutting edge located at an intersection of the second upper surface and the second side surface, one or more second groove portions located at the second side surface, reaching the second upper surface, and dividing the second cutting edge, a land which is on the second upper surface and extends along the second cutting edge, and a cutting edge reinforcement portion located at an end portion closer to the second cutting edge on the second upper surface, wherein a length of the cutting edge reinforcement portion is longer than a length of the land, in a direction approximately vertical to the second cutting edge, and the cutting edge reinforcement portion comprises a protuberant portion which is located above the land as viewed from the side surface of the second cutting insert; and a holder configured to install the first cutting insert and the second cutting insert thereto, wherein the first cutting insert and the second cutting insert are installed to the holder, in such a manner that the first cutting edge and the second cutting edge are located at an outer peripheral side of the holder, the first lower surface and the second upper surface are opposed to each other, and a rotational locus of the cutting edge reinforcement portion and a rotational locus of the first groove portion overlap partly.