The present disclosure relates to a rhomboid-shaped double-sided turning insert having a convex cutting corner flanked by two flank faces, wherein the insert comprises, on each side: a rhomboid-shaped rake face opposite the face of the opposite side; a lateral cutting corner surface arranged adjoining and between the two flank faces; two flanking edges, each formed between a respective flank face and a rhomboid side of the rake face; a cutting edge formed by a straight primary cutting edge and a straight secondary cutting edge, formed between the lateral cutting corner surface and the rake face, arranged adjoining and between the two flanking edges, wherein the primary cutting edge is longer than the secondary cutting edge; and a chip-deflecting surface which is recessed and arranged inwardly of said cutting edge; wherein a lateral cutting corner surface of the insert, formed by the lateral cutting corner surfaces of a first and a second side, extends between the first side and second side cutting edges, wherein the primary cutting edge and secondary cutting edge are in reversed positions between the first and second sides.

A cutting element, which is configured for the machining of a non-metallic composite material composed of a matrix and particles held together by the matrix, has a flank face, a rake face and a cutting edge which is coated with an edge coating and via which the flank face and the rake face are connected to one another, with which the non-metallic composite material can be machined in an improved fashion. The cutting edge within a cutting edge section thereof is curved in such a way that the cutting edge immediately beneath the edge coating in a section in a section plane that is perpendicular to the cutting edge has, at every point of the cutting edge section, a local radius of curvature which is greater than or equal to 10 μm and less than or equal to 80 μm.

A cutting insert according to an aspect includes a base portion and a cutting portion. The cutting portion includes a front end surface, an top surface, a first lateral surface, a second lateral surface, a front cutting edge, and a lateral cutting edge. The front cutting edge includes a first cutting edge and a second cutting edge, and a radius of curvature of the first cutting edge is greater than a radius of curvature of the second cutting edge.

A cutting insert in a non-limiting embodiment may include a first surface, a second surface, a third surface and a land surface. The first surface may include a first corner and a first side extended from the first corner. The land surface may be located between the first surface and the third surface and inclined relative to the first surface and the third surface. The land surface may include a first land surface located along the first corner, a second land surface located along the first side, and a third land surface having a concave shape which is adjacent to the second land surface and located further away from the first land surface than the second land surface.

A coolant supply mechanism is attachable to a cutting insert. The cutting insert has a first bottom surface, a first upper surface, and a first side surface. The first upper surface includes a corner portion that is located at a corner of the first upper surface when viewed in a plan view and that is contiguous to the first side surface so as to form a cutting edge, and a center portion located adjacent to the corner portion on a side opposite to the cutting edge when viewed in a plan view. The first upper surface is depressed toward the first bottom surface side at the center portion.

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.

A cutting insert rotatable about an axis, has opposing front and rear surfaces interconnected by an insert peripheral surface, the insert peripheral surface having first and second side surfaces spaced apart by first and second land surfaces. First and second land edges extend along the first and second land surfaces, respectively. A first front edge formed at the intersection of the front surface and the first side surface includes a cutting-edge portion, and a second front edge formed at the intersection of the front surface and the second side surface is devoid of a cutting-edge portion. A cutting profile formed by rotating the cutting-edge portion about the axis is located axially forward of the second front edge. The cutting insert is releasably secured to a tool shank, the cutting insert being located between two protuberances protruding from a forward end portion of the tool shank.

A cutting insert that suppresses softening of joint material in a joint surface between a sintered body and a base body to improve the joint strength, and that enables size reduction of the sintered body, is provided. The cutting insert includes a sintered body having a cutting edge, and a base body having a leading end where the sintered body is joined via a braze material. The sintered body includes a front surface on a leading side, an upper surface connected to the front surface and forming the cutting edge with the front surface along a connecting edge with the front surface, a bottom surface opposite the upper surface, a back surface opposite the front surface, and two side surfaces. The sintered body and base body are joined together in a joint surface including the bottom surface and back surface of the sintered body. The joint surface in side view has a step-like shape with a leading side thereof being lower than a trailing side thereof.

In a cutting tool having an indexable lay-down cutting insert with a central body portion and three circumferentially spaced apart cutting portions, the cutting insert is removably secured to an elongated holding portion of an insert holder. Each cutting portion has a cutting edge with first and second cutting end points, the cutting edge formed at the intersection of an upward facing rake surface and a radially outward facing relief surface. In a top view of the cutting insert, parallel imaginary first and second vertical planes containing the first and second cutting end points, intersect the central body portion at first and second body side points, which are located first and second cutting distances from the first and second cutting end points, respectively. Each of the first and second cutting distances is greater than twenty-five percent of the first radius of an imaginary first circle circumscribing the cutting insert.

A cutting insert includes an upper surface and a cutting edge. The upper surface includes a first surface and a second surface which is located further inward than the first surface. The cutting edge includes a first cutting edge and a second cutting edge. The first surface includes a first region along the first cutting edge, a second region adjacent to the first region, and a third region which is adjacent to the second region and along the second cutting edge. The second surface includes a fourth region, a fifth region and a sixth region. A width of the second region is smaller than each of a width of the first region and a width of the third region. An inclination angle of the fifth region is smaller than each of an inclination angle of the fourth region and an inclination angle of the sixth region.