| 摘要 |
The technical objective of the present invention is to provide a cutting insert capable of increasing strength of a cutting edge while reducing interference with a workpiece. To this end, the cutting insert of the present invention includes an upper plane, a lower plane, a side connecting the upper plane and the lower plane, and a cutting edge part formed between the upper plane and the side. Moreover, the cutting insert is fastened to a tool holder. The upper plane and the side make an acute angle with each other, and the lower plane and the side make an obtuse angle with each other. The upper plane includes a first edge part of width, a first lengthwise edge part, a second edge part of width and a second lengthwise edge part sequentially along the circumference thereof. Each of the first and the second lengthwise edge part has a concavely indented shape. |
