A cutting tool which may be used in machining various material may include a body and one or more cutting elements associated therewith. In one example, the cutting element(s) may comprise a superhard table, such as a polycrystalline diamond table. In some embodiments, the polycrystalline diamond table may have a diamond density of approximately 95 percent volume or greater. In some embodiments, the thickness of the superhard table may be approximately 0.15 inch. In some embodiments, the superhard table may include a chip-breaking feature or structure. Methods of shaping, finishing, or otherwise machining materials are also provided, including the machining of materials comprising titanium.

A cutting insert of the present disclosure includes a top surface, a bottom surface, a side surface, and a corner cutting edge, a first cutting edge, a second cutting edge and a third cutting edge formed at a ridge line formed by the side surface and the top surface. The corner cutting edge has a first end and a second end. The first cutting edge extends from the first end in a first direction. The second cutting edge extends from the second end in a second direction. The third cutting edge extends from the second cutting edge in a third direction. The top surface has a first rake face adjacent to the first cutting edge, a second rake face adjacent to the second cutting edge, and a third rake face adjacent to the third cutting edge.

A cutting insert is mountable on a body. The cutting insert includes: a top surface; a bottom surface opposite to the top surface; a side surface contiguous to the top surface and the bottom surface; and a cutting edge formed at a ridgeline between the top surface and the side surface. The side surface has a first surface disposed adjacent to the cutting edge and a second surface contiguous to the first surface. When viewed in a cross sectional view parallel to the bottom surface, the second surface has a first position and a second position that are brought into abutment with the body when mounted on the body. Between the first position and the second position, an imaginary straight line extending through the first position and the second position is separated from the second surface.

A cutting insert which is excellent in both cutting edge strength and chip evacuation is provided. A corner edge of the cutting insert is formed in an arc shape. In a direction perpendicular to a rotation axis of a body, a width of the corner edge is 40% or more and 50% or less of a width of the cutting insert. An upper surface has a negative land which is formed along a cutting edge and has a negative angle. The angle of the negative land increases from one end, which is connected to an inner cutting edge, of both ends of the corner edge toward the other end.

A ridgeline between the top surface and the side surface includes: a nose cutting edge portion having a curved line shape, the nose cutting edge portion having a first end and a second end opposite to the first end; a major cutting edge portion contiguous to the first end; and a wiper cutting edge portion contiguous to the second end. The top surface includes: a first rake face contiguous to the wiper cutting edge portion; a second rake face contiguous to the major cutting edge portion; and a third rake face contiguous to the nose cutting edge portion and contiguous to each of the first rake face and the second rake face. A boundary line between the second rake face and the third rake face is separated from the first end and is contiguous to the major cutting edge portion.

The first seating surface is contiguous to each of the front end surface and the outer circumferential surface. The second seating surface is contiguous to the front end surface. The cutting tool body is provided with a recess contiguous to each of the first seating surface, the second seating surface, and the front end surface. When the front end surface is viewed in a direction from the front end surface toward the rear end surface, a length of the recess in a direction perpendicular to a straight line parallel to the central axis and extending along the first seating surface is equal to or longer than three times as long as a length of the recess in a direction perpendicular to the first seating surface and passing through a contact point of the second seating surface, the recess, and the front end surface.

A cutting insert which is excellent both in manufacturing performances and dimensional precision and forms a pair with a tool body and a gear cutter including the cutting insert are provided. A cutting insert has a first face which is a rake face, a second face, a peripheral side face, and a mounting hole. On a ridge line where the first face and the peripheral side face cross each other, a cutting blade is formed. The cutting blade includes a corner part capable of machining a tooth bottom of a gear, and a main part extending to the corner part. The peripheral side face includes an inner side face in contact with a tool body and a first flank facing the main part. The mounting hole penetrates the first flank and the inner side face so that a center axis crosses the inner side face perpendicularly. The cutting insert is formed having a wedge shape such that thickness of the first flank and the inner side face becomes smaller as it goes from one end to the other end.

An insert may include a first surface, a second surface, a ridge line located at an intersection of the first surface and the second surface. The first surface may include a first corner, a first side and a second side. The ridge line may include a corner cutting edge located on the first corner, a first cutting edge located on the first side, and a second cutting edge located on the second side. The first surface may further include a first region located from the first cutting edge toward a midportion of the first surface, a second region located from the second cutting edge toward the midportion of the first surface, and a concave part located on at least one of the first region and the second region.