Image Number 4 for United States Patent #6217264.
Disclosed is a cutting insert capable of enhancing the surface roughness of worked materials and lengthening the durability of a cutting tool which has utilized in conjunction with the cutting insert, capable of efficiently removing cut chips from the cutting region by making a chip breaker into a complete free curved surface to discharge the cut chips in the most natural direction and form, which are formed when performing a desired cutting operation of ferrous or nonferrous metals such as aluminum, copper, stainless, etc., to also minimize the resistance to chip flow and the occurrence of the melted-sticking phenomenon. The cutting insert has a specific chip breaker formed on an upper surface thereof with the aid of a pressure molding operation using a mold and in a sintering operation. A lower surface of the cutting insert is formed as a plane. The lower surface is firmly fixed on a holder for cutting tool and supports the cutting insert when mounting the cutting insert in the holder for cutting tool. It is also possible to provide the chip breaker on the lower surface. At least one cutting corner is formed at corners of the upper surface. The cutting insert includes main cutting edge portions slanted to the cutting corner at a certain angle. The main cutting edge portions includes main cutting edges and main cutting edge land surfaces extend from the main cutting edges toward the upper surface. A circle opening is formed through the center of the cutting insert. A boss is mounted in the circle opening.