A cutting insert (10) for a tool (100) for machining a workpiece. The cutting insert (10) is a four-bladed cutting insert which is in the form substantially of a rhomboid. The cutting insert (10) has two identical, oppositely arranged base sides (14a, 14b) and four identical main sides (16a-16d) which extend between the two base sides (14a, 14b). Each of the four main sides (16a-16d) comprises a rectilinear main cutting edge (12a-12d) and a rectilinear secondary cutting edge (26a-26d) which is arranged transversely thereto. The main and secondary cutting edges (12a-12d) and (26a-26d) of each main side (16a-16d) lie in each case in a common cutting plane which is aligned parallel to a contact surface (28a-28d) which is also provided on the main sides (16a-16d).

A cutting insert for profile turning, in particular for wheel profile turning, includes an upper surface, a lower surface, and side surfaces. At the transition from the upper surface to the side surfaces two cutting edges are formed for machining a workpiece and two further edges each having two ends. The two cutting edges are designed part-circular in shape and each extend from one end of one of the two edges to the opposite end of the other of the two edges. Also described is a cartridge for holding a cutting insert, the cartridge being mountable on a machine tool. The cartridge has a main seating surface having a plane angle () of greater than 90 to the axis of rotation (D) of the workpiece.

There is provided a cutting insert having a low possibility that chips roughen a machined surface of a workpiece in back turning. The cutting insert includes a rake surface, a peripheral side surface, a front cutting edge which is provided on a ridge of the rake surface and the peripheral side surface, and a main cutting edge which is provided on the ridge so as to be continuous with the front cutting edge and has an extension direction which forms an obtuse angle with an extension direction of the front cutting edge, the main cutting edge is curved into a U shape over an entire length of an effective edge range which functions as a cutting blade, and the deepest point of the U shape is positioned in a range closer to a side of a corner than a position which divides a straight line connecting both ends of the main cutting edge at a ratio of 2:1 from the side of the corner positioned adjacent to the front cutting edge.

Provided is a cutting tool that simultaneously improves both fracture resistance and wear resistance. The cutting tool according to the present invention has an end surface, a peripheral side surface intersecting with the end surface, and a cutting edge in an intersecting ridge part along the end surface and the peripheral side surface, and when first and second points A and B are defined on the cutting edge, the first point A protrudes further toward an outer side of the cutting tool than the second point B. The cutting edge has a honing surface. The honing surface has a portion, the width of which gradually increases from the first point A toward the second point B.

A cutting insert according includes a first surface and a cutting edge. The first surface includes a first inclined surface and a projection. The first inclined surface includes a first region located close to a first corner portion, a second region located close to a second corner portion, and a third region located between the first region and the second region. The projection includes a first projection located close to the first corner portion and a second projection located close to the second corner portion. A first top portion of the first projection is located closer to the first corner portion than a first boundary portion between the first region and the third region, and a second top portion of the second projection is located closer to the second corner portion than a second boundary portion between the second region and the third region.

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 device for mechanically removing material from a workpiece or bulk feedstock, thereby creating chips of removed material while producing a new surface on the workpiece or bulk feedstock. The device comprises a body and at least one round cutting insert that is tangentially mounted on the body. Location and orientation of the insert is characterized by a reference plane offset and an insert axis angle. The insert has an outwardly-facing rake surface on which chips are formed. A planar flank surface is oriented relative to a cutting motion so as to provide clearance between the cutting insert and the surface created by removal of a layer that is converted into chips. A circular cutting edge lies at the intersection of the flank and rake surfaces.

A cutting tool according to an aspect of the present invention is a cutting tool for cutting a rotationally symmetrical surface of a rotating workpiece. The cutting includes the step of feeding the cutting tool in a direction inclined with respect to a rotational axis of the rotationally symmetrical surface, while holding the cutting tool in contact with the rotationally symmetrical surface. In the step of feeding the cutting tool, the cutting tool has a point that is in contact with the rotationally symmetrical surface and the point shifts as the cutting tool is fed. The cutting tool includes: a rake face; a flank face; and a cutting edge connecting the rake face and the flank face. The cutting edge as seen from above the flank face has a shape including at least one arc, and the arc has a radius of curvature of not less than 100 mm and not more than 500 mm.

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.