A cutting insert for a tool for machining a workpiece. The cutting insert comprises a rake face with a chip shaping geometry which is particularly suitable for machining titanium and titanium alloys. The chip shaping geometry is designed in such a way that the chip lifted from the workpiece is deformed comparatively strongly about its longitudinal axis. The chip shaping geometry is arranged at least in a rear area of the rake face, which is laterally bounded by a first concavely curved portion and a second concavely curved portion of the minor cutting edges of the cutting insert. The chip shaping geometry projects upwardly beyond a cutting plane in which the main cutting edge of the cutting insert and two rectilinear portions of the two minor cutting edges are arranged and comprises at least two elevations so that the rake face in the rear area in a further cross-section parallel to the main cutting edge comprises two high points and an intermediate second low point which has an equal third distance from the first concavely curved portion and the second concavely curved portion. A rake angle along the main cutting edge varies such that the rake angle ?1 at a center of the main cutting edge, which has an equal second distance from a first end and a second end of the main cutting edge, is greater than the rake angle in the area of the first and/or second ends.

Indexable, double-sided turning inserts for turning operations and and a turning tool are provided with cutting edges at alternating corners on opposite sides of the insert. Chipbreaker structures can be provided without interfering with providing large supporting surfaces. When the insert is used in a cutting operation, chips from one of the cutting edges in use are unlikely to damage cutting edges that are not in use but are on adjacent corners.

Provided is a cutting tool for back turning capable of improving chipping resistance. A cutting tool wherein a wall surface of a chip breaker includes a first wall surface that is formed along a first ridgeline, and a reinforcing surface that is connected to the first wall surface and a first end surface at an end portion of the chip breaker on the side of a first cutting edge, and that forms an angle of 90 degrees or an obtuse angle with the first end surface.

Provided is a cutting insert that improves chip control performance. In a cutting insert for back turning process, a chip breaker wall face, of a chip breaker, facing the axial feed direction includes: when viewed from a first face side, a first wall face portion configured so that a ridgeline connecting a top portion of the chip breaker and the first wall face portion is a straight line; and a second wall face portion connected to the first wall face portion on a first cutting edge side and configured so that a ridgeline connecting the top portion of the chip breaker and the second wall face portion is closer to a second cutting edge side than the straight line.

The edge portion includes an upper surface, a side surface, and a land surface. The side surface has a front side surface and a pair of lateral side surfaces. An intersection between the land surface and the front side surface forms a front cutting edge. An intersection between the land surface and each of the pair of lateral side surfaces form a corresponding one of a pair of lateral cutting edges. The edge portion contains 80 vol % or more of diamond. A chip breaker recess is provided between the upper surface and the land surface. The surfaces forming the chip breaker recess include a rake face and a breaker wall surface. The upper surface has a front edge portion opposite to the front cutting edge from the chip breaker recess. A pair of protruding portions are provided to extend from the front edge portion toward the front cutting edge.

There is provided a throw-away tip which includes a blade containing diamond and is excellent in chip processability. The throw-away tip comprises a body and a blade provided to the body and having a cutting edge, the blade containing 80% by volume or more of diamond, the blade having a land surface extending along the cutting edge, and a chip breaker having a recess located opposite to the cutting edge with the land surface therebetween, the recess having a side surface having an inclined surface that recedes continuously as a distance thereof from the land surface increases in magnitude and that has a shape identical to that of a portion of a side surface of a shape of a body of revolution.

A cutting insert (1) includes at least one cutting edge (8) formed on an intersecting ridge line portion between a rake surface (6) and a flank (7), and at least one ridge (12). The cutting edge includes a cutting edge portion (9) extending along a corner portion (5) and a straight-line shaped cutting edge portion (10) connecting to the cutting edge portion (9). The ridge (12) is formed to rise on the rake surface (6). The ridge (12) extends from a portion of a rake surface inside the cutting edge portion of the corner portion toward a rake surface inside the straight-line shaped cutting edge portion.

A cutting element has a cutting head and a shaft. The cutting head is carried by the shaft and protrudes over the shaft transversely relative to a longitudinal extent of the shaft. The cutting head has a cutting edge, the cutting edge follows a circle segment with a circle center at a side of the shaft located in a virtual cutting head plane and is constructed symmetrically, when viewed in a direction perpendicular to the cutting head plane, with respect to a virtual cutting edge axis of symmetry which is contained in the cutting head plane. The cutting head has a chip guiding structure. The chip guiding structure is associated with the cutting edge, has a chip guiding groove and a plurality of chip guiding elements. Each chip guiding element has a longitudinal rib and a transverse rib.

A turning insert for machining both Inconel and Titanium workpieces. The insert includes a chip forming arrangement including only a single v-shaped groove. The groove includes a specific depth and position to improve machining of both Inconel and Titanium work pieces.

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.