A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert of a substantially horizontal cylindrical segment shape is described. The cutting insert comprises top and bottom surfaces having a circular segment shape. The cutting insert further comprises a convex side. The cutting insert further comprises a flat side. The cutting insert further comprises a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert further comprises a hole extending from the convex side towards the flat side. The hole is positioned at a center of a surface of the flat side.

A cutting insert may include a first surface, a second surface, a third surface, and a land surface. The first surface may include a first corner, a first side, and a second side. The land surface may be inclined relative to the first surface and the third surface. The land surface may include a first land surface connecting to the first corner. An imaginary flat surface orthogonal to a central axis connecting a center of the first surface and a center of the second surface may be a reference plane, a first inclination angle of a part of the first land surface which connects to a midportion of the first corner may be larger than a second inclination angle of a part of the first land surface which connects to an end portion at a side of the first side of the first corner.

A cutting insert of a substantially horizontal cylindrical segment shape may include top and bottom surfaces having a circular segment shape. The cutting insert may include a convex side and a flat side. The cutting insert may include a top cutting edge which is formed where the convex side and the top surface meet, and a bottom cutting edge which is formed where the convex side and the bottom surface meet. The cutting insert may include a hole extending from the convex side towards the flat side. The hole may be positioned at a center of a surface of the flat side.

Provided is a cutting insert having two cutting parts that is capable of entering a workpiece more deeply and easily supports machining of a groove or hole having a small diameter in a workpiece. A cutting insert includes: a body having at least an inner surface to be fixed to a tool body of a cutting tool and an outer surface opposed to the inner surface; and two cutting parts protruding in opposite directions in a longitudinal direction of the body. The cutting part includes: a cutting upper surface; a cutting front surface; and a first cutting side surface and a second cutting side surface. A front cutting edge is located on an edge between the cutting upper surface and the cutting front surface. In a projection view of the body as seen from the longitudinal direction, the cutting upper surfaces of the two cutting parts are oriented in directions opposed to each other, and front cutting edges of the two cutting parts are disposed so as to be more away from each other as being closer to the first cutting side surface from the second cutting side surface.

A cutting crown fixing for positively locking and non-rotatable fixing of a cutting crown to a holder associated therewith of a comminuting apparatus, in particular a rotor of a comminuting apparatus, including a cutting crown, a cutting crown holder associated with the cutting crown, a screw bolt and a thread insert having a head portion and a shaft portion, wherein the thread insert has a female thread complementary to the male thread of the screw bolt and the cutting crown holder has a through passage for receiving the screw bolt, and in the installed position the thread insert is arranged in positively locking relationship in the axial and tangential direction in a holding opening of the cutting crown associated therewith. The cutting crown holder according to the invention is distinguished in that the positively locking configuration of a peripheral surface of the thread insert relative to the holding opening of the associated cutting crown extends over the entire longitudinal extent of the thread insert, wherein the thread insert is of a rotationally symmetrical configuration over the longitudinal extent of the head portion for providing an axial positively locking relationship with the holding opening and at least over a longitudinal portion has a conical peripheral surface which in the installed position corresponds to a conical receiving portion of complementary configuration of the holding opening and the thread insert in the region of the longitudinal extent of the shaft portion is of a non-rotationally symmetrical configuration for providing a rotational positively locking relationship with the holding opening.

A cutting tool holder of the present disclosure includes a bar-shaped main body. The main body includes a first pocket to receive a first insert, a second pocket to receive a second insert, a first groove extending from the first pocket, and a second groove extending from the second pocket. The first groove includes a second opening located on a rear side in a rotation direction, and the second groove includes a fourth opening located on a rear side in the rotation direction in a cross section orthogonal to a rotation axis. An angle θ1 formed by the second opening and an outer peripheral surface of the main body is smaller than an angle θ2 formed by the fourth opening and the outer peripheral surface of the main body in a cross section orthogonal to the rotation axis.

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 γ1 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.

A cutting insert includes a bottom surface, a top surface opposite to the bottom surface, and a cutting edge portion. The cutting edge portion is located on the same side as the top surface. The cutting edge portion is formed of a sintered material including cubic boron nitride particles. A volume ratio of the cubic boron nitride particles to the sintered material is more than or equal to 50 percent. The cutting edge portion includes a rake face, a flank face contiguous to the rake face, and a cutting edge located along a ridgeline between the rake face and the flank face. The rake face is inclined toward the bottom surface so that a distance from the rake face to the bottom surface decreases gradually toward the cutting edge.