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 having a thermal conductivity within the range of 20 to 70 W/m.Math.K and including cubic boron nitride particles having an average particle diameter within the range of 0.5 m to 2 m; 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.

In a cutting tool having an indexable cutting insert with three cutting portions, the cutting insert is removably securable to an insert holder by means of a fastener. The cutting insert has two opposing end surfaces with a peripheral side surface extending therebetween. At least one end surface has a central boss protruding therefrom with a raised support surface, and the peripheral side surface has three abutment recesses. In an end view of the cutting insert, each of the three abutment recesses is visible and located inside a first imaginary circle circumscribing the visible central boss. A holding portion of the insert holder has a seating surface with at least one protuberance protruding therefrom. The support surface is in clamping contact with the seating surface, and exactly two of the three abutment recesses are engaged with the at least one protuberance.

A cutting insert includes a body having three vertices, an upper face, a lower face, and six planar flank faces perpendicular to and joining the upper and lower faces. A cutting edge is formed at an intersection between the upper and lower faces and each of the planar flank faces. A triangular-shaped island surrounds a central axis, A, of the cutting insert and is higher in elevation than the upper and lower faces. A tool holder includes a tool holder body having a generally triangular-shaped insert-receiving pocket with a triangular-shaped recess that is substantially identical in shape to the triangular-shaped island of the cutting insert that interacts with the island to properly locate and prevent rotation of the cutting insert when mounted in the tool holder.

According to the present disclosure, a cutting insert includes an upper surface having a polygonal shape and includes a corner, a side surface adjacent to the upper surface, a cutting edge and a protrusion. The cutting edge is located at a ridge part in which the upper surface intersects with the side surface and includes a corner part located at the corner. The protrusion is located on the upper surface. The protrusion includes a first protrusion on a bisector of the corner in a top view. The protrusion further includes a second protrusion adjacent to the first protrusion in a direction orthogonal to the bisector. The second protrusion is closer to the corner than the first protrusion in the top view.

A method to form a surface on a metal work piece includes providing a turning insert that has a nose angle formed between first and second cutting edges less than or equal to 85; providing a turning tool having a tool body with an insert seat in which the turning insert is mountable; arranging the orientation of the second cutting edge such that it forms a back clearance angle of more than 90 in a feed direction; rotating the metal work piece around a rotational axis in a first direction; moving the turning insert in a direction parallel to or at an angle less than 45 relative to the rotational axis; and setting the longitudinal axis of the tool body at an angle greater than zero but less than or equal to 90 relative to the rotational axis of the metal work piece.

A cutting insert including a body having three vertices, an upper face, a lower face, and flank faces joining the upper and lower faces. At least one cutting edge is formed at an intersection between the upper face and the flank faces. A generally triangular-shaped island surrounds a central axis of the cutting insert and is higher in elevation than at least one portion of the upper face.

A cutting tool includes a two-way indexable cutting insert retained in a tool holder by a clamping member. The cutting insert has a tetrahedral basic shape and includes two cutting edges at opposite ends of thereof. The insert holder includes a forwardly located mounting portion that includes three spaced apart mounting jaws which together define an insert receiving pocket having a pocket opening. The clamping member is attached to the insert holder body so that a clamping portion of the clamping member protrudes into the pocket opening. When the cutting insert is releasably attached to the insert holder in a fastened position of a cutting tool, the cutting insert is located in the insert receiving pocket and clampingly engaged therein by the clamping portion.

A method to form a surface on a metal work piece includes providing a turning insert having a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first and second cutting edges, a nose angle formed between the first and second cutting edges being less than or equal to 85; arranging the second cutting edge such that it forms a back clearance angle of more than 90 in a feed direction; positioning all parts of the turning insert ahead of the nose cutting edge in the feed direction; rotating the metal work piece around a rotational axis in a first direction; and moving the turning insert in a direction parallel to or at an angle less than 45 relative to the rotational axis, such that the surface at least partly is formed by the nose cutting edge.

A cutting tool having a tool holder, cutting insert and clamping member. The tool holder includes an elongated supporting surface extending in a rearward-to-forward direction. The cutting insert has a central portion and three cutting portions, the central portion having two opposing side surfaces and three spaced apart locating surfaces defining a first imaginary triangle. The cutting insert is indexable about a central axis intersecting the two side surfaces. Each locating surface intersects two of three bisector planes containing the central axis and bisecting respective corners of the first imaginary triangle, and the cutting edge of each cutting portion is located entirely outside of the first imaginary triangle. In each index position the clamping member is located entirely rearward of a first vertical plane containing the central axis and perpendicular to the rearward-to-forward direction, and one of the locating surfaces is in clamping contact with the supporting surface.

A turning insert includes a top surface, an opposite bottom surface, a reference plane located parallel to and between the top surface and the bottom surface, and a center axis extending perpendicular to the reference plane and intersecting the reference plane (RP), the top surface and the bottom surface. Side surfaces connect the top surface and the bottom surface. Three nose portions are formed symmetrically relative to the center axis. Each nose portion includes a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first) and second cutting edges. In a top view the first and second cutting edges on the same nose portion form a nose angle of 25-50 relative to each other. The distance from the first cutting edge to the reference plane varies in such a way that that this distance is decreasing at increasing distance from the nose cutting edge.