A cutting insert may include a first surface, a second surface, a third surface, and a land surface. The first surface may include a first corner, a first side, and a second side. The land surface may be inclined relative to the first surface and the third surface. The land surface may include a first land surface connecting to the first corner. An imaginary flat surface orthogonal to a central axis connecting a center of the first surface and a center of the second surface may be a reference plane, a first inclination angle of a part of the first land surface which connects to a midportion of the first corner may be larger than a second inclination angle of a part of the first land surface which connects to an end portion at a side of the first side of the first corner.

A cutting insert includes an upper surface and upper edge. The upper surface includes a second side part, a first corner part, and a second corner part. The upper surface further includes a first surface and a second surface. The upper edge includes a first edge located at the first corner part, a second edge located at the second side part, and a third edge located at the second corner part. The second surface includes a first region extending toward the first corner part, and a second region extending toward the second corner part. A distance between the first region and the upper edge is smaller at a side of the second edge than at a side of the first edge. A distance between the second region and the upper edge is smaller at a side of the second edge than at a side of the third edge.

A turning insert for machining both Inconel and Titanium workpieces. The insert includes a chip forming arrangement including only a single v-shaped groove. The groove includes a specific depth and position to improve machining of both Inconel and Titanium work pieces.

A cutting edge includes a nose portion, a first cutting edge portion, and a second cutting edge portion. When a boundary between a first inclined portion and a first breaker portion, a boundary between a first step surface and a second breaker portion, a boundary between a second inclined portion and a third breaker portion, and a boundary between a second step surface and a fourth breaker portion are a first position, a second position, a third position, and a fourth position, respectively, the second position is higher than the first position and the fourth position is higher than the third position in a direction perpendicular to the seating surface, and a distance between the first position and the third position is greater than a distance between the second position and the fourth position in a direction parallel to the seating surface.

A cutting edge tip of a cubic boron nitride sintered body has improved joint strength to a substrate of a cemented carbide. A cutting edge tip of a cubic boron nitride sintered body has improved crater wear resistance. A tool 10 of the present invention includes a substrate 12 of a cemented carbide and a cutting edge tip 14 of a cubic boron nitride sintered body joined to the substrate 12. The cutting edge tip 14 has a thickness covering an upper surface 12a to a lower surface 12b of the substrate 12. The cubic boron nitride sintered body contains 50 volume % or more and 95 volume % or less of cubic boron nitride and 5 volume % or more and 50 volume % or less of a binder phase. The cubic boron nitride has an average grain size of 1.0 m or more and 6.0 m or less.

An insert includes a first surface having a corner portion, a second surface, a third surface, and a cutting edge. The cutting edge is provided with a first cutting edge located on the corner portion and a second cutting edge adjacent to the first cutting edge, and the third surface is provided with a first portion located along the first cutting edge and a second portion located along the second cutting edge. the second portion includes a first region having a first end portion and a second end portion, and a second region having a third end portion and a fourth end portion. An inclination angle 212 at the second end portion is greater than an inclination angle 211 at the first end portion, and an inclination angle 222 at the fourth end portion is smaller than an inclination angle 221 at the third end portion.

A cutting insert according to an aspect includes a top surface and a side surface. At least a part of a ridge line where the top surface and the side surface intersects is a cutting edge. The cutting edge includes a first portion located at a corner portion, a second portion adjacent to the first portion, a third portion close to the second portion, a fourth portion close to the third portion, and a fifth portion adjacent to the fourth portion. When viewed from directly above, a curvature radius of the second portion is less than a curvature radius of the first portion, a curvature radius of the third portion is greater than the curvature radius of the first portion, and a curvature radius of the fourth portion is less than the curvature radius of the third portion.

A cutting insert may include a first surface, a second surface, a third surface and a cutting edge. The first surface may include a corner, a first side, a first inclined surface located along the corner, a second inclined surface located further inside than the first inclined surface, a third inclined surface located along the first side, a fourth inclined surface located further inside the first surface than the third inclined surface, and a protruded part located further inside than the second inclined surface and the fourth inclined surface. An inclination angle of the protruded part may be smaller than an inclination angle of the second inclined surface in a cross section along a bisector of the corner. The inclination angle of the protruded part may be larger than a third inclination angle in a cross section orthogonal to the first side.

A cutting tool according to this invention includes a cutting edge configured to cut a workpiece; a rake surface configured to come in contact with a chip, which appears when the workpiece is cut by the cutting edge; and a relieved surface configured to come in contact with a to-be-cut surface of the workpiece. A plurality of first grooves are formed on a cutting edge side of the rake surface. The plurality of first grooves includes a plurality of aligned grooves arranged adjacent to each other, and a connection groove connecting at least two of the plurality of aligned grooves to each other.

A cutting insert includes an upper surface and upper edge. The upper surface includes a second side part, a first corner part, and a second corner part. The upper surface further includes a first surface and a second surface. The upper edge includes a first edge located at the first corner part, a second edge located at the second side part, and a third edge located at the second corner part. The second surface includes a first region extending toward the first corner part, and a second region extending toward the second corner part. A distance between the first region and the upper edge is smaller at a side of the second edge than at a side of the first edge. A distance between the second region and the upper edge is smaller at a side of the second edge than at a side of the third edge.