A coated cutting tool includes a substrate with a rake side, a clearance side and a cutting edge, and a coating including a first layer and a second layer. The second layer includes an inner layer and an outer layer, wherein the first layer is exposed through an opening in the inner layer and the opening extends over at least a portion of the width of the cutting edge. Thereby, a double layer is provided in critical areas, whereas a single layer is provided in other areas. Preferably, the double oxide layer includes aluminum oxide layers. A method for manufacturing the coated cutting tool is also provided.

A cutting tool for cutting a hard brittle material is formed from a light-transmittable material through which laser light can pass and is provided with a rake angle, the laser light is propagated through the cutting tool, the cutting tool and the hard brittle material are brought into contact with each other, the laser light is incident to at least a contact part where the cutting tool and the hard brittle material are in contact with each other and a part with the rake angle, the laser light except for Fresnel reflection light on an end surface of the cutting tool is incident to the hard brittle material through the contact part and the rake angle part to soften the hard brittle material, and the softened hard brittle material is cut.

A cutting insert includes a cutting edge having an involute-curve approximate shape. A cutting edge is formed so as to wholly take on a first curved shape with a first curvature radius when the cutting insert is viewed from the end surface, and is formed so that a large part of the cutting edge takes on a second curved shape with a second curvature radius when the cutting insert is viewed from the side surface.

The invention concerns a cutting insert comprising an upper and a lower surface and one or more edge surfaces which connect the upper surface and the lower surface together, wherein provided at the transition of at least one edge surface at least to the upper surface is at least one cutting edge, wherein the upper surface adjoining the cutting edge is in the form of a chip surface and the edge surface adjoining the cutting edge is in the form of a tool flank. To provide a cutting insert in which the chip break range is enlarged and the risk of damage to the cutting insert and/or the tool and/or the workpiece by coiling chips is reduced it is provided according to the invention that at least one recess is provided in the tool flank at a spacing from the cutting edge.

An insert includes a rake angle set corresponding to the hardness of a material to be cut and that can suppress an increase in the material cost even when the strength of a cut edge section is increased. The insert has a polygonal shape and includes a cutting edge portion on at least one side of the polygonal shape. The cutting edge portion includes a rake face having a convex formed on one of opposite surfaces in the thickness direction a flank face having a concave formed on a surface intersecting with the one surface in the thickness direction and a concave cutting edge that is formed between the rake face and the flank face.

An indexable cutting insert is suitable for vertical and oblique machining. The cutting insert has top and bottom surfaces, first to fourth side surfaces extending between the top and bottom surfaces, and a screw hole passing through the top and bottom surfaces. The top surface has a mounting surface of a flat surface. The top and bottom surfaces are rotationally symmetric with each other. A cutting edge is formed at a junction between the top surface and the adjacent first and second side surfaces. A non-cutting edge is formed at a junction between the top surface and the adjacent third and fourth side surfaces. The first and second side surfaces form an acute angle with a plane extending from the mounting surface of the top surface. The third and fourth side surfaces form an obtuse angle with the plane extending from the mounting surface of the top surface.

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 includes a cutting insert comprising a top surface, a bottom surface, a clamping surface for abutting a clamp, a cutting edge, a hole extending through the insert from the bottom surface to the clamping surface, and a channel extending from the clamping surface to proximate the cutting edge, and a tool holder comprising a tool holder body having a pocket for receiving the insert, a clamp for contacting the clamping surface and clamping the insert in the pocket, and a tool holder passage in the body in flow communication with the hole in the insert. A cutting insert is also provided.

A physical configuration of multiple-layer coatings formed with at least one layer of coating containing cubic born nitride (cBN) particles with one or more layers in composite form containing cBN particles may have a thickness of each individual layer as thin as in the nanometer range, or as thick as in the range of a few microns and even up to tens of microns. The chemistry of the composite layer consists of any individual phase of (a) nitrides such as titanium nitride (TiN), titanium carbonitride (TiCN), and hafnium nitride (HfN); (b) carbides such as titanium carbide (TiC); and (c) oxides such as aluminum oxide (AI.sub.2O.sub.3) or any combination of the above phases, in addition to cBN particles. The coating or film can be stand-alone or on a substrate.

An object is to prolong the life of a cubic boron nitride cutting tool used for cutting a heat-resistant alloy. A cubic boron nitride cutting tool includes an edge tip made of a sintered cubic boron nitride compact including cubic boron nitride particles; and a base metal that holds the edge tip at a corner portion of the base metal, wherein a cutting edge formed on the edge tip of the tool has a positive rake angle.