A cutting insert in a non-limiting embodiment 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 extended from the first corner. The land surface may be located between the first surface and the third surface and inclined relative to the first surface and the third surface. The land surface may include a first land surface located along the first corner, a second land surface located along the first side, and a third land surface having a concave shape which is adjacent to the second land surface and located further away from the first land surface than the second land surface.

A single-crystal diamond cutting tool is provided with a flank and a rake face, a cutting edge being provided at a boundary between the flank and the rake face, an inclined surface being provided at a location distant from the cutting edge, the inclined surface being contiguous to the rake face and inclined at 0.05 degrees or more and 80 degrees or less with respect to the rake face, the rake face having a roughness Ra of 1 .Math.m or less, the cutting edge being provided with a chamfered surface or round honing having a width of 1 .Math.m or less, the cutting edge having projections and depressions having a width of 100 nm or less and smaller than that of the chamfered surface or round honing.

A turning insert includes a head portion connected to a stem portion. A CBN cutting edge includes a surface generating cutting edge and two major cutting edge portions, such that each major cutting edge portion forms an angle of 5-20° in relation to a tangent line of the cutting edge at a forward point of the cutting edge.

The invention relates to a cutting insert (1) for installation in carrier tools for machining workpieces, comprising a top side (2), a bottom side (3), and side surfaces (4) connecting the top side (2) and the bottom side (3), wherein a peripheral protective chamfer (5) having an upper edge (6) adjoining the top side (2) of the cutting insert (1) and having a lower edge (7) adjoining the side surfaces (4) is arranged at the transition from the top side (2) to the side surfaces (4), wherein the upper edge (6) forms cutting edges (9) and cutting corners (10) and, in the region of the cutting edges (9), the lower edge (7) transitions into a cutting-edge clearance angle surface (8) having an edge clearance angle of 3° to 11°. For improved edge stability in drawn cuts, it is proposed that, in the region of the cutting corners (10), the lower edge (7) of the protective chamfer (5) transitions into a corner clearance angle surface (11) having an edge clearance angle of 3° to 5°.

A cutting insert includes a body having an upper face, a lower face, a plurality of planar flank faces joining the upper and lower faces, and a plurality of curved flank faces joining the plurality of flank faces. A T-land is formed at a downward sloping angle with respect to the upper face. A cutting edge is formed at an intersection of a respective flank face and the T-land. A curved cutting edge is formed at an intersection of a respective curved flank face and the T-land. A micro-channel is formed in one of the flank faces, the curved flank faces and the T-land and proximate one of the cutting edge and the curved cutting edge.

A cutting tool comprises a rake face and a flank face, the cutting tool being composed of a substrate made of a cubic boron nitride sintered material and a coating provided on the substrate, the coating including a MAlN layer, when a cross section of the MAlN layer is subjected to an electron backscattering diffraction image analysis to determine a crystal orientation of each of the crystal grains of the M.sub.xAl.sub.1−xN and a color map is created based thereon, then on the color map, the flank face having the MAlN layer occupied in area by 45% to 75% by crystal grains of the M.sub.xAl.sub.1−xN having a (111) plane with a normal thereto extending in a direction within 25 degrees with respect to a direction in which a normal to the flank face extends, the MAlN layer having a residual stress of −2 GPa to −0.1 GPa.

A cutting insert has a surface that relates to cutting, the surface comprising cBN sintered material, ceramics, or cermet. The cutting insert comprises: a rake face; a flank face; a chamfer located between the rake face and the flank face; and a cutting edge formed by a ridgeline at which the flank face and the chamfer intersect. The cutting edge comprises a cutting edge portion for push cutting, a cutting edge portion for pull cutting, and a connecting cutting edge portion located between the cutting edge portion for push cutting and the cutting edge portion for pull cutting. In the chamfer located along the cutting edge, the chamfer located along the connecting cutting edge portion has a minimum width.

A surface-coated cutting tool includes a base material and a coating covering the base material. The base material includes a rake face and a flank face. The coating includes a TiCN layer. The TiCN layer has a (422) orientation in a region d1 in the rake face. The TiCN layer has a (311) orientation in a region d2 in the flank face.

A cutting tool including a rake face, a flank face, and a cutting edge portion, comprising a substrate and an AlTiN layer, the AlTiN layer including cubic Al.sub.xTi.sub.1-xN crystal grains, Al having an atomic ratio x of 0.7 or more and 0.95 or less, the AlTiN layer including a central portion, the central portion at the rake face being occupied in area by (200) oriented crystal grains at a ratio of 80% or more, the central portion at the flank face being occupied in area by (200) oriented crystal grains at a ratio of 80% or more, the central portion at the cutting edge portion being occupied in area by (200) oriented crystal grains at a ratio of 80% or more.

The throwaway insert includes a base and a cutting edge member. The cutting edge member includes a rake face, a flank face, a first connecting face, a second connecting face, and a first ridgeline serving as a cutting edge. The rake face includes a main surface and a first chamfer provided at an edge tip portion of the cutting edge member, the edge tip portion including an extreme tip portion of the cutting edge member. In a plan view from an upper surface of the base, the flank face, the first connecting face, and the second connecting face are located external to the base. The first chamfer is inclined relative to the main surface so as to increase a thickness of the cutting edge member as the first chamfer is closer to the main surface.