A cutting insert and an indexable insert-type cutting tool includes a cutting edge (6A) formed on each of a pair of side ridge portions of at least one of the side faces, wherein an insert main body (1) is formed in the shape of having front-back inversion symmetry which is 180 rotationally symmetrical with respect to a line of symmetry (N) passing through the center of the side faces; a flank face adjacent to the cutting edge (6A) is formed on the side face in the vicinity of each of the pair of polygonal faces (2); each of the flank faces is formed in the shape of a twisted face; the pair of side ridge portions on which the cutting edge (6A) is formed intersect each other in such a manner that the second corner portion (B) of one side ridge portion protrudes outside the other side ridge portion.

[Object] To provide a cutting tool having good chipping resistance and good wear resistance. [Solution] Provided is a cutting tool 1 including a base body 2 whose surface is coated with a coating layer 6 made of Cr.sub.aM.sub.1-a (C.sub.1-xN.sub.x) (here, M is at least one element selected from Ti, Al, Si, W, Mo, Ta, Hf, Nb, Zr, and Y, 0.01a0.4, and 0x 1), a cutting edge 5 is formed on an intersection ridgeline between a rake face 3 and a flank face 4, and the coating layer 6 for the cutting edge 5 has a Cr content ratio greater than a Cr content ratio of the coating layer 6 for the flank face 4.

An object of the present invention is to configure a cutting-off processing tool that includes a cutting edge angled at an end cutting edge angle and causes evacuation of chips to be controlled so that the chips are evacuated in the tool axis direction, thereby reducing concerns about damage to a processed surface by the chips. The cutting-off processing tool includes a cutting edge angled at the end cutting edge angle. In the cutting-off processing tool, an upper surface has a shape laterally asymmetric about a center in a width direction. In the cutting-off processing tool, when b is a rake angle of a rake face on a first corner side positioned on a foremost end of the tool, and c is a rake angle of the rake face on a second corner side, b>c is satisfied.

A cutting element for use in a cutting operation, comprising a cutting edge (CE) capable of cutting out material from a workpiece during the operation, to form therein a workpiece corner of angle alpha. There exists at least one view of the cutting edge in which a portion of the cutting edge is delimitable by a first (L1) and a second (L2) line oriented tangentially to the portion of the cutting edge portion at respective tangency points A and B. The lines form therebetween a cutting angle corresponding to the workpiece corner angle alpha and have a vertex 0. For a bisector of the cutting angle intersecting the portion of the cutting edge at the point C, the projection C of the point C of the portion of the cutting edge on a line OL passing through the vertex 0 perpendicularly to the plane of the one view is located between projections A1 and B of the respective points A and B of the portion of the cutting edge on the line OL.

A groove insert to be received in a tool holder has, along its top and bottom side and on its rear side, a holding structure which is formed by holding faces which taper toward one another and by way of which the groove insert is fixed in the tool holder in a positive locking manner. The tool holder has corresponding counter faces. The groove insert and the tool holder form a groove cutting tool.

To provide a cutting tool that includes a coating layer capable of exhibiting optimum cutting performance in each of a cutting edge, rake face, and flank face. A cutting tool (1) includes a substrate (2) that is coated with a coating layer (6) composed of Si.sub.aM.sub.1-a(C.sub.1-xN.sub.x), where M represents at least one element selected from Ti, Al, Cr, W, Mo, Ta, Hf, Nb, Zr, and Y, 0.01a0.4, and 0x1, and that has a cutting edge (5) at an intersecting ridge line of a rake face (3) and a flank face (4). The Si content ratio in the coating layer (6) on the rake face (3) is higher than that on the cutting edge (5).

A coated cutting tool has a base material of a WC-based cemented carbide and a film formed on the surface of the base material by a chemical vapor deposition method. The coated cutting tool has a rake face, a flank face and a cutting edge ridgeline part positioned between the rake face and the flank face being provided, wherein a total film thickness of the entire film is 3 to 20 m in an average film thickness, and one or more oblique cracks where an extension angle of the crack to the surface of the film is 45 or less are present at the rake face within 300 m from the cutting edge ridgeline part.

A cutting tool for performing cutting operations on a workpiece when the cutting tool is rotated about a central axis by a machine tool, the cutting tool includes a generally cylindrical body disposed about the central axis. The generally cylindrical body includes a first end and an opposite second end. The cutting tool further includes a cutting portion and a mounting portion. The cutting portion is disposed at or about the first end of the generally cylindrical body and includes a number of cutting edges structured to engage the workpiece during cutting operations. The mounting portion is disposed at or about the opposite second end of the generally cylindrical body and is structured to be coupled to the machine tool. At least a portion of the generally cylindrical body comprises a molded portion formed via a molding process about the cutting portion in a manner that couples the cutting portion to the generally cylindrical body.

An indexable milling cutting insert includes an opposed outside and inside, a periphery, and a plurality of homologous and alternately individually usable cutting edges, which are equidistantly spaced apart from a centre axis, which extends between the outside and inside. The cutting insert includes a plurality of countersunk chip channels, which are delimited by bottoms and tangentially spaced-apart ridges, which individually include a cutting edge formed between a chip surface included in a first chip channel, and a clearance surface, which borders on a second chip channel.

A tool, a toolholder and a tool-toolholder unit obtained by coupling tool and toolholder is adapted to be fixed to a rotor of a shredder. The tool and the toolholder have a coupling mechanism that permit a quick and easy assembly or disassembly of the two elements and ensure, at the same time, a stable and safe fixing during use of the tool.