An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

An indexable cutting insert has a central mounting portion and two cutting portions. The central mounting portion has opposing upper and lower surfaces. The lower surface has two abutment elements associated therewith, each abutment element having two diverging abutment surfaces forming two abutment angles. The two cutting portions extend away from the central mounting portion, have distal cutting edges, and are entirely located in diagonally opposite imaginary quadrants of four quadrants defined by two mutually perpendicular quadrant planes. Two abutment bisector planes bisecting the two abutment angles and one of the quadrant planes are parallel or coincident. In a top view, the two cutting portions extend away from the central mounting portion in opposite directions. Two cutting bisector lines parallel to the two directions and bisecting the two cutting edges are mutually offset. A cutting tool has an insert holder and the cutting insert removably retained therein.

A cutting insert for an indexable drill according to the present disclosure may be used for external cutting or internal cutting depending on a position and a direction in which the cutting insert is installed even though a single type of cutting insert is provided. In addition, the cutting insert for an indexable drill according to the present disclosure has a section of the internal cutting edge which is involved in a cutting process or a section of the internal cutting edge which is not involved in the cutting process, which are clearly distinguished from each other, and as a result, the cutting insert may be rotated and mounted, and reversed and mounted on a drill body, such that maximum eight corners may be used to perform a cutting process.

A cutting insert is used in a cutting edge replaceable rotary cutting tool. The cutting insert includes a first cutting edge formed on an intersecting ridge portion between a first end surface of two opposite end surfaces and a circumferential side surface, and a first depressed portion formed along a part of the first cutting edge. The first depressed portion is provided to form a larger rake angle at the first cutting edge than that at a part not having the first depressed portion of the first cutting edge.

An indexable cutting insert has opposing first and second polygonal end surfaces (2, 3) connected by a peripheral side surface (4). Sets of cutting edges (5) are formed at the intersection of each end surface with the peripheral side surface. Each set of cutting edges includes a corner cutting edge (6), first and second cutting edges (7), (8) on opposite sides of the corner cutting edge (6) and a wiper edge (9) formed between the second cutting edge (8) and the corner cutting edge (6). The peripheral side surface (14) includes a wiper-edge side surface (14) having constant width as it extends between the first and second end surfaces (2, 3). A boundary of the wiper-edge side surface (14) with a second side surface below the second cutting edge (8) is inclined with respect to a direction perpendicular to the first end surface.

An indexable cutting insert has opposing first and second polygonal end surfaces (2, 3) connected by a peripheral side surface (4). Sets of cutting edges (5) are formed at the intersection of each end surface with the peripheral side surface. Each set of cutting edges includes a corner cutting edge (6), first and second cutting edges (7), (8) on opposite sides of the corner cutting edge (6) and a wiper edge (9) formed between the second cutting edge (8) and the corner cutting edge (6). The peripheral side surface (14) includes a wiper-edge side surface (14) having constant width as it extends between the first and second end surfaces (2, 3). A boundary of the wiper-edge side surface (14) with a second side surface below the second cutting edge (8) is inclined with respect to a direction perpendicular to the first end surface.