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.

A cutting tool comprising a cutting tool holder and a cutting insert adapted to be mounted thereon. The tool holder comprises an insert seat defined by a base and at least one side wall extending from the base to define an insert seat space adapted to receive therein the insert. The seat comprises a support element extending into the insert seat from the base, and a fastening member engageable with the seat. The fastening member is displaceable with respect thereto between a mounting position adapted to allow the insert to be mounted onto the seat and a securing position adapted for securing the insert within the seat. The insert is formed with a securing cavity and when the insert is mounted onto the tool holder and is in the securing position, a portion of the support element and the fastening member is received within the cavity of the insert.

A cutting insert mounting system adapted for a cutting tool in which, by using a tightening screw, a cutting insert is detachably mounted on an insert mounting seat. A central axis of a screw hole of the insert mounting seat is inclined with respect to a normal direction of a bottom wall surface of the insert mounting seat. When the cutting insert is placed on the insert mounting seat, on a virtual plane defined to expand the bottom wall surface, a central axis of the screw hole is shifted from the central axis of a through hole of the cutting insert to the side of one of two side wall surfaces of the insert mounting seat. On the virtual plane, an axis shift direction of the central axis of the screw hole and an inclination direction of the central axis of the screw hole are different.

A cutting tool assembly has a cutter body, a clamp pin, a cutting insert and a set screw. The clamp pin is inserted to the cutter body to secure the cutting insert to an insert pocket. The set screw is fastened to a threaded hole of the cutter body to press the clamp pin toward the insert pocket. A side surface of the cutting insert contacts a side wall of the insert pocket at a first contact portion. A head of the clamp pin contact an inner peripheral surface of a bore of the cutting insert at a second contact portion. The first and second contact portions are located such that a moment acts on the cutting insert toward the base wall of the insert pocket around the first contact portion.