US Patent 8449224 Cutting tool and cutting method

A cutting tool of the invention is equipped with a cutting insert comprising an upper surface, a lower surface, a side surface connected to the upper surface and the lower surface, and an upper surface side cutting edge and a lower surface side cutting edge formed at an intersection portion between the upper surface and the side surface and at an intersection portion between the lower surface and the side surface, respectively; and a holder comprising at a front part thereof an insert pocket to which the cutting insert is attached. The insert pocket comprises a bearing seat surface against which the lower surface of the cutting insert abuts, and is opened into a front surface and a side surface of the holder, respectively. At least one of a first intersection portion lying at an intersection portion between the bearing seat surface of the insert pocket and the front surface of the holder, and a second intersection portion lying at an intersection portion between the bearing seat surface of the insert pocket and the side surface of the holder, lies more outward than the lower surface side cutting edge of the cutting insert. A cutting method using the cutting tool is also provided.