A cutting insert of one embodiment is provided with: an insert body having a top surface that has a corner section, a bottom surface, and side surfaces; a cutting edge that is positioned at an intersection between the top surface and the side surfaces, and includes a corner cutting edge, a first cutting edge and a second cutting edge; a rake face that slopes downward away from the cutting edge; and a first raised part that is positioned inside the rake face, and rises upward. The first raised part includes a protruding section that protrudes toward the corner cutting edge. The cutting insert is further provided with a second raised part that extends toward the first cutting edge and the second cutting edge from the protruding section, and has a convex curved shape in which, when viewed from above, the outer peripheral edge on the corner section side.

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.

The present invention provides a cutting tool which has a flat top face but still has excellent chip control. The cutting tool includes: a peripheral side face; a top face which is a flat top face constituting a part of an upper surface that is depressed except for the portion of the top face; a cutting edge that is formed at least on a ridge line of a corner R connecting two linear ridge lines, out of ridge lines where the peripheral side face and top face cross; and a fan-shaped rake portion including ridge portions and groove portions, which are disposed alternately and are both depressed so as to be inclined from the corner R, where the crossing line with the top face appears in a wave form, toward a pivot portion which is a center of radial portions.

A cutting insert includes a body having an upper face, a lower face, a plurality of planar flank faces, bidirectional acute cutting corners and bidirectional obtuse cutting corners joining two adjacent flank faces. A land has a varying width. An annular island includes a plurality of bulged extensions, relatively longer and narrower chip breaking points proximate the acute cutting corners, and relatively shorter and wider chip breaking points proximate the obtuse cutting corners. A chip breaking ramp surface flanks each of the relatively longer and narrower chip breaking points and each of the relatively shorter and wider chip breaking points. The chip breaking ramp surfaces form a series of non-collinear lines that are at a non-zero angle with respect to the cutting edge.

Inclined surfaces are formed on a rake face and a recessed groove is formed in the central portion between the inclined surfaces. A groove width of the recessed groove gradually increases from the position of the end cutting edge toward the rear, then gradually decreases such that the recessed groove has a narrowest portion at a position P2 forward of the position P3 of an upper end of a breaker wall and rearward of a positive rake angle rear end position P1, and then gradually increases toward the rear up to the position P3 of the upper end of the breaker wall. The dimensional relation W1<W2<W3 holds, where W1 is the groove width at the end cutting edge, W2 is the groove width at the narrowest portion, and W3 is the groove width at the position P3 of the upper end of the breaker wall.

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 cutting insert for a machining tool having a cutting edge and a flute extending along the cutting edge is described. A chip breaker element which projects into the interior of the flute is disposed in the flute. Said chip breaker element comprises a chip guiding surface and each point of the chip guiding surface has a spacing from a flute contour that is greater than zero. The chip guiding surface furthermore either extends parallel to the flute contour and/or curved along two directions. A machining tool having such a cutting insert is presented as well.

A cutting insert may include an upper surface, a lower surface, a front cutting edge and a first lateral cutting edge. The upper surface may include a breaker protrusion. The first lateral cutting edge may include an inclined part which is closer to the lower surface as going away from the front cutting edge. The breaker protrusion may include a first region, a second region and a third region. The first region may be located further away from the lower surface than the inclined part. The second region may be located closer to the front cutting edge than the first region, and may be located closer to the lower surface than the inclined part. The third region may be located further away from the front cutting edge than the first region, and may be located closer to the lower surface than the inclined part.

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 cutting tool in which chip control is improved. A cutting edge member includes a first wall surface which includes a concave surface which is formed to be depressed in a direction away from an intersection point of an imaginary plane and a corner portion and toward the center of a cutting insert in an end view when viewed from a direction facing an end surface, a second wall surface which includes a convex surface which is provided to be connected to the first wall surface at a position spaced apart from the imaginary plane and is protruded in a direction away from the center of the cutting insert in the end view, a third wall surface which includes a convex surface which is provided to be connected to the first wall surface at a position spaced apart from the imaginary plane on an opposite side to the second wall surface across the imaginary plane and is protruded in a direction away from the center of the cutting insert in the end view, and a fourth wall surface which is provided in an area between the first wall surface and the intersection point in the end view, includes a convex surface which is protruded in a direction away from the center of the cutting insert in the end view, and has a height smaller than heights of the second wall surface and the third wall surface in a side view when viewed from a direction facing a side surface.