A cutting insert may include a base and a cutting part. The cutting part may include an upper surface, a first cutting edge and a second cutting edge. The first cutting edge may be located on a first ridgeline. The second cutting edge may be located on a second ridgeline. The upper surface may include a first inclined surface, protrusions and a first upheaved part. The first inclined surface may be located along the first ridgeline. The protrusions may be located side by side in a direction along the first ridgeline on the first inclined surface. The first upheaved part may be located at a side further away from the first ridgeline than the pair of protrusions. The second cutting edge may be inclined downward. An upper end of the first upheaved part may be located above the second cutting edge.

A cutting insert includes an upper surface, a lower surface, a side surface, and a cutting edge. The upper surface includes a first side part, a second side part, and a corner part located between the first side part and the second side part. The side surface is located between the upper surface and the lower surface. The cutting edge is located at an intersection of the upper surface and the side surface. The cutting edge includes a first cutting edge located at the corner part, and a second cutting edge adjacent to the first cutting edge and located at the first side part. A height of the first cutting edge relative to the lower surface is constant. The second cutting edge is inclined toward the lower surface as going toward the corner part.

A modular drill including a shank having a shank bore therein, a guide pin tip disposed in the shank bore, a cutting tip, and a connection shaft coupled to the cutting tip, the connection shaft having a connection shaft sidewall and a guide path therein for guiding the guide pin tip therethrough while the connection shaft moves through the shank bore.

A cutting insert has a seating surface, an outer peripheral surface, a top surface, and an attachment hole. The cutting edge includes a curved cutting corner edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face contiguous to the first cutting edge portion, a second rake face contiguous to the second cutting edge portion, and a third rake face contiguous to the cutting corner edge portion and also contiguous to the first and second rake faces. The third rake face has a first region contiguous to the first rake face and a second region contiguous to the second rake face. The first rake face and the first region each have a rake angle which is a positive angle. The second rake face and the second region each have a rake angle which is a negative angle.

A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge.

A cutting insert for a cutting tool includes a cutting edge of PCBN or PCD formed in a corner region in a transition between a side surface and a chamfer formed in an upper side of the cutting insert. A chip breaker is formed in the chamfer inside of the cutting edge, extending between a lower chamfer portion and an upper chamfer portion. The chip breaker includes a chip breaker bottom connected to the lower chamfer portion and a chip breaker wall extending from the upper chamfer portion to the chip breaker bottom. An upper transition is formed between the upper chamfer portion and the chip breaker wall. As seen in a top view, the upper transition follows a smoothly curved path including a convex middle portion. As seen in cross-section, perpendicular to the cutting edge, the chip breaker wall and the chip breaker bottom form a smooth concave profile.

A cutting insert may include a first surface having a polygonal shape, a second surface, a third surface and a cutting edge. The first surface may include a first corner, a first side, a first inclined surface located along the first side, and a second inclined surface located along the second side. In a plan view of the first surface, a width of the first inclined surface in a direction orthogonal to the first side may become larger as approaching the second side. A width of the second inclined surface in a direction orthogonal to the second side may become larger as approaching the first side.

A cutting insert has a cutting portion corner formed at the intersection of a rake surface, a forward cutting portion surface and a relief surface. A cutting edge is formed at an intersection of the rake surface and the relief surface with a land that is located on the rake surface and that extends along, and negatively away from, the cutting edge. A chip-control arrangement is located at the rake surface and includes an elongated projection and plurality of spaced apart elongated protuberances that extend from the projection to the cutting edge, so that the land has a plurality of spaced apart bulging land portions. A non-rotary cutting tool has an insert holder having an insert pocket and the cutting insert releasably retained therein.

A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge.

A cutting insert has a top surface, a seating surface, and an outer peripheral surface. The cutting edge includes a corner cutting edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face, a second rake face, a third rake face, a front side surface, an upper surface, a first side surface, and a second side surface. A ridgeline between the first side surface and the second side surface is continuous to the upper surface. When seen in a direction perpendicular to the seating surface, a width of a boundary between the front side surface and the third rake face is larger than a width of a boundary between the front side surface and the upper surface.