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 and a first side. The land surface may be located between the first surface and the third surface. The land surface may include a first land surface connecting to the first corner, and a second land surface connecting to the first side. A width of the first land surface in a front view as viewed from a side of the first surface may be a first width, the first width at an end portion on a side of the second land surface may be larger than the width at a part connecting to a midportion of the first corner.

A turning tool includes a turning insert and a tool body. The turning insert has opposite facing top and bottom surfaces connected by a circumferential side surface. The turning tool has a pocket arranged for receiving the turning insert. The pocket includes a bottom support surface and first and second pocket side surfaces, the first and second pocket side surfaces forming an acute angle. The first pocket side surface includes first and second side support surfaces and the second pocket side surface includes third and fourth side support surfaces. The first recess is formed between the first and second side support surfaces and the second recess is formed between the third and fourth side support surfaces. Each recess forms a gap between the circumferential side surface and the respective pocket side surfaces.

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.

An insert based on an aspect includes a first surface having a corner portion, a second surface, a third surface, and a cutting edge located on at least part of a portion on which the first surface and the third surface intersect. 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. Additionally, 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 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 part of a cutting insert may include a first surface including a corner, a first side, a first region, a second region and a third region. The first region may be located along the corner and the first side. The second region may be located at a more inner part than the first region. The third region may be located at a more inner part than the second region. A boundary between the corner and the first side may be a first point. A boundary between the first region and the second region may be a second point in a cross section that passes through the first point and is orthogonal to the first side. An imaginary straight line passing through the first point and the second point may be a first imaginary straight line. The first imaginary straight line may intersect with the third region.

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 tool assembly includes a shank, a shim, a cutting insert, a clamping lever and a set screw. The shank has an insert pocket with a base wall, a lever receiving portion and a screw hole. The shim is disposed on the base wall of the insert pocket and has a shim bore. The cutting insert is disposed on the upper surface of the shim and has an insert bore. The clamping lever is received in the lever receiving portion and clamps the cutting insert to the insert pocket. The clamping lever has first and second extension portions. The set screw is fastened to the screw hole and has a screw head, a threaded portion and an engaging groove. The engaging groove of the set screw engages the second extension portion. The shim includes an avoiding portion for avoiding an interference with the screw head.

A cutting insert of one aspect includes a top surface including a corner portion and a pair of side portions each adjacent to the corner portion, a bottom surface, a side surface located between the top surface and the bottom surface, and a corner cutting edge disposed at the corner portion. In such a cutting insert, the top surface includes a first rake surface located along the corner cutting edge, a raised portion located farther on the inner side than the first rake surface, and a second rake surface located between the corner cutting edge and the raised portion. Moreover, a rake angle at a first region of the second rake surface corresponding to a center of the corner cutting edge is greater than a rake angle at a second region of the second rake surface located beside the first region.

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.