A cutting tool insert includes eight identical cutting edges. Each separate cutting edge has a first cutting edge portion and a second cutting edge portion. A corner angle between the first cutting edge portion and the second cutting edge portion is within a range of 75 to <90 degrees. The first cutting edge portion and the second cutting edge portion have substantially the same length to provide a substantially equal cutting depth. As seen along the center axis of the insert a first angle within a range of 14+/−9 degrees is formed between a first imaginary line extending from the center axis to a corner point at the first side surface and a second imaginary line extending from the center axis to an adjacent corner point at the second side surface. A cutting tool insert holder is also disclosed.

A swiss insert includes a chip former arrangement. The chip former arrangement includes a ridge separated on each side from a cutting edge's sub-edge by a chip surface. In a side view, each sub-edge extends in a straight line.

A cutting tool with a device for the prevention of uncontrolled chip formation which are placed in a specific distance to a cutting edge at a layer of polycrystalline diamond (PCD) or polycrystalline boron nitride (PCBN), and to a manufacturing process for the production of such a cutting tool. The PCD or PCBN layer incorporates the device for the prevention of uncontrolled chip formation as an integral part, and the layer with the device for the prevention of uncontrolled chip formation and the cutting edge are produced by way of an additive procedure, or that the device and the cutting edge are produced by removing material of the PCD or PCBN body by laser or electro-erosion.

A turning insert includes a top surface, an opposite bottom surface, and a reference plane therebetween. A center axis intersects the top and bottom surfaces and a side surface connects the top and bottom surfaces. A circular cutting edge is adjacent the top surface and the side surface. The top surface includes a set of first protrusions, which are elongated in a direction parallel to the adjacent cutting edge.. A greatest distance from the reference plane to the first protrusions is greater than a distance from the reference plane to the cutting edge. The bottom surface has a set of radial grooves and includes a set of flat surfaces. The flat surfaces extend in a plane parallel to the reference plane, wherein in a top view each first protrusion is symmetrical in relation to a line extending between the center axis and a mid-point of the first protrusion.

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.

An indexable drill insert (10) includes a top surface (12), a bottom surface (14), and a plurality of side surfaces (16) adjoining the top surface (12) and the bottom surface (14). A plurality of cutting edges (20) is formed by an intersection of a respective side surface (16) with the top surface (12). One aspect of the invention is that the top surface (12) includes a protruding portion (50) having a backwall (50a) and a segmented portion (52) extending radially outwardly with respect to the protruding portion (50) for effective chip breaking. Another aspect of the invention is that a rake surface (48) has a positive rake angle (RA) that varies along a first cutting edge section (22) of the cutting edge (20) to lower cutting force.

A cutting insert for drilling includes an upper surface, a lower surface formed on an opposite side of the upper surface, a side surface connecting the upper surface and the lower surface; a cutting edge formed at an intersection of the upper surface and the side surface, and a ridge portion formed to protrude upward from the upper surface to facilitate chip control. The ridge portion includes a ridge body spaced apart from the cutting edge and disposed at a central portion of the cutting insert for drilling; and a ridge extension portion extending from a vicinity of a corner of the ridge body in a direction parallel to the cutting edge.

There is provided a machining assembly and cutting insert for machining metal or like workpieces, wherein the cutting insert body has a cutting end. The cutting end comprises at least one cutting edge and at least one cutting lip formed adjacent the at least one cutting edge. The at least one cutting lip includes at least one cutting protrusion and associated chip cutting edge to split the chip formed by the at least one cutting edge, for producing chips during machining which are of a width that is sufficiently reduced to allow proper evacuation or removal.

A cutting insert according to the present disclosure includes a first raised portion and a second raised portion stepped from the first raised portion, which are formed on a top surface and along a center line connecting the center of the corner portion and the center of the top surface. The first raised portion is located closer to the corner portion than the second raised portion is, and the first raised portion is inclined downwardly from the second raised portion toward the corner portion. The second raised portion is formed at a higher position from the bottom surface than the first raised portion, and a side portion connected to the first raised portion is inclined downwardly from the second raised portion toward the first and second cutting edges.

A turning insert has two opposite main surfaces and a peripheral surface which extends therebetween and has N side surfaces, where 2<N<9. The insert has mirror symmetry about a mid-plane and 360/N degree rotational symmetry about a central axis perpendicular to the mid-plane. The insert has two main edges which each have N main cutting edges and N corner cutting edges. Each main cutting edge has two raised edge portions and a lowered edge portion. Each main surface has N main rake surfaces and N corner rake surfaces. Each main surface further has at least N convex island protrusions and N at least partially convex peninsula protrusions, any and all island protrusions associated with a given main rake surface being located between two adjacent peninsula protrusions, each pair of adjacent peninsula protrusions having at least one island protrusion located therebetween.