A turning insert has two opposite main surfaces and a peripheral surface which extends therebetween and has N side surfaces, where 2<N<9. The insert has mirror symmetry about a mid-plane and 360/N degree rotational symmetry about a central axis perpendicular to the mid-plane. The insert has two main edges which each have N main cutting edges and N corner cutting edges. Each main cutting edge has two raised edge portions and a lowered edge portion. Each main surface has N main rake surfaces and N corner rake surfaces. Each main surface further has at least N convex island protrusions and N at least partially convex peninsula protrusions, any and all island protrusions associated with a given main rake surface being located between two adjacent peninsula protrusions, each pair of adjacent peninsula protrusions having at least one island protrusion located therebetween.

The present disclosure relates to a cutting insert, and a cutting insert according to the present disclosure comprises: an upper surface and a lower surface oriented in opposite directions; a first and a second shorter side surface connecting the upper surface and the lower surface to each other and oriented in opposite directions; a first and a second longer side surfaces connecting the upper surface and the lower surface to each other, connecting the first and the second shorter side surfaces to each other, oriented in opposite directions, and being longer than the first and the second shorter side surfaces; and a through hole extending through the upper surface and the lower surface, wherein when viewed toward the upper surface, the first longer side surface has two side portions, each side portion having an inclined shape with reference to the center portion.

A cutting insert has a top surface, a seating surface, and an outer peripheral surface. The cutting edge includes a corner cutting edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face, a second rake face, a third rake face, a front side surface, an upper surface, a first side surface, and a second side surface. A ridgeline between the first side surface and the second side surface is continuous to the upper surface. When seen in a direction perpendicular to the seating surface, a width of a boundary between the front side surface and the third rake face is larger than a width of a boundary between the front side surface and the upper surface.

Chip discharge during high-feed machining and low-feed machining particularly in a high-depth-of-cut state or the like is improved so as to allow so-called freedom of feed during cutting to be improved. A cutting edge body of a cutting insert includes a front cutting edge formed on one end side in a longitudinal direction, the front cutting edge being a cutting edge formed on an intersecting edge between a peripheral side surface and an upper surface of the cutting edge body having a prismatic shape, a side cutting edge formed on one end side in a lateral direction, a recessed part provided in the upper surface of the cutting edge body to be subsequent to the side cutting edge in the lateral direction, and a wall part having a wavy wall surface formed in a portion of the recessed part and a discrete wall surface formed at a position between the wavy wall surface and the side cutting edge and including a plurality of surfaces which are discrete along the longitudinal direction.

A cutting insert according to an aspect includes a base portion and a cutting portion. The cutting portion includes an upper surface, a side surface, a ridge line including a first ridge line and a second ridge line, and an intersection point. The upper surface includes a top surface region and a rising surface region located between the top surface and the ridge line, and having a shape protruding toward the intersection point. In a top view, a first distance from the first ridge line to the rising surface increases as close to the intersection point, and a second distance from the second ridge line to the rising surface increases as close to the intersection point.

A cutting insert according to an aspect includes a base portion and a cutting portion. The cutting portion includes an upper surface, a side surface, a ridge line including a first ridge line and a second ridge line, and an intersection point. The upper surface includes a top surface region and a rising surface region located between the top surface and the ridge line, and having a shape protruding toward the intersection point. In a top view, a first distance from the first ridge line to the rising surface increases as close to the intersection point, and a second distance from the second ridge line to the rising surface increases as close to the intersection point.

A rotatable tool, comprising a tool support body which has an axis and which forms at least one plate seat either directly or in a cartridge in order to receive a cutting plate. By means of a head screw, which passes through the cutting plate, the base of the cutting plate can be pressed against a base support surface, and two plate edges, which form an angle with each other, can be pressed against a respective corresponding edge support surface of the plate seat. Production dimensions are maintained with a low degree of tolerance and the tool is protected from excessive wear to a sufficient degree. Both edge support surfaces are made of support bodies which are movably guided in the tool support body and which can be driven by a corresponding adjustment device in order to finely adjust the cutting plate in a radial and axial direction, respectively.

A rotatable tool, comprising a tool support body which has an axis and which forms at least one plate seat either directly or in a cartridge in order to receive a cutting plate. By means of a head screw, which passes through the cutting plate, the base of the cutting plate can be pressed against a base support surface, and two plate edges, which form an angle with each other, can be pressed against a respective corresponding edge support surface of the plate seat. Production dimensions are maintained with a low degree of tolerance and the tool is protected from excessive wear to a sufficient degree. Both edge support surfaces are made of support bodies which are movably guided in the tool support body and which can be driven by a corresponding adjustment device in order to finely adjust the cutting plate in a radial and axial direction, respectively.

A turning insert includes a top surface, an opposite bottom surface, a side surface connecting the top and bottom surfaces, and a cutting edge formed at an intersection between the top surface and the side surface. The cutting edge including a corner cutting edge, a first cutting edge, and a second cutting edge. The top surface having a first surface in the form of a depression, which borders at least a major portion of the corner cutting edge. The first and the second cutting edges subtending an angle θ which is 75-85°. At least a part of the corner cutting edge is concave in a front view.

A cutting insert comprises: a body; and a blade fixed to the body and made of a polycrystalline cubic boron nitride including 98.5% by volume or more of cubic boron nitride, the blade having a rake face and a flank face, the rake face and the flank face meeting each other and thus forming a ridge line which serves as a cutting edge, the rake face being provided with a land surface extending along the cutting edge, and a chip breaker disposed on a side opposite to the cutting edge with the land surface therebetween and also having a recess contiguous to the land surface.