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 is provided, comprising a top surface, a bottom surface, and side surfaces spanning therebetween, the side surfaces comprising one or more feed-facing side surfaces and one or more radial-facing side surfaces. The top surface is formed with one or more linear grooves, each constituting a chip breaker and being disposed parallel to and adjacent one of the feed-facing side surfaces. The chip breaker is characterized by a constant profile along the entire length of its respective feed-facing surface. Each of the feed-facing side surfaces is disposed at an acute feed-angle with respect to the top surface, and each of the radial-facing side surfaces being disposed at an acute radial-angle with respect to the top surface, the feed-angle being greater than the radial-angle.

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.

When seen in a direction perpendicular to a seating surface, the second boundary line has a first portion and a second portion, the first portion having an inclination relative to the second cutting edge portion in a counter clockwise direction, the first portion being located between the first boundary line and an intersection between the second boundary line and a straight line passing through a center of a mounting hole and perpendicular to the second cutting edge portion, the second portion being located opposite to the first portion relative to the intersection, the second portion having an inclination relative to the second cutting edge portion in a clockwise direction.

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 provide adaptability to a wide range of cutting conditions during low depth and high depth cutting and during low-feed and high-feed machining and allow so-called freedom of feed during cutting to be improved. A cutting insert includes a cutting edge body and a substrate to which the cutting edge body is joined. The cutting edge body has a prismatic shape having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction and includes a cutting edge formed on an intersecting edge between a peripheral side surface and an upper surface of the cutting edge body having the prismatic shape and a recessed part formed at a position on the upper surface of the cutting edge body which is more distant from the intersecting edge than from the cutting edge. The substrate has a projected part upwardly projecting from the upper surface of the cutting edge body.

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.

The invention relates to a cutting tool for machining, in particular for a peeling-like machining process, comprising a chip-forming depression which runs along the cutting edge and in which elevated chip-forming elements are formed. According to the invention, the elevated chip-forming elements have an elongated contour with a length which is greater than the width, in plan view, such that the chip-forming elements have a rising flank and a falling flank. The rising flank, which is longer by comparison, is defined by a rising angle (α) of 3° to 20°, preferably 5° to 10°, and a falling angle (β) of 25° to 45°, preferably 27° to 35°, and the transition between the rising flank and the falling flank is rounded, the radius (R) of said rounded section ranging between 0.05 mm and 1 mm, preferably between 0.25 mm and 0.4 mm.

A cutting part of a cutting insert may include a first surface including a corner, a first side, a first region, a second region and a third region. The first region may be located along the corner and the first side. The second region may be located at a more inner part than the first region. The third region may be located at a more inner part than the second region. A boundary between the corner and the first side may be a first point. A boundary between the first region and the second region may be a second point in a cross section that passes through the first point and is orthogonal to the first side. An imaginary straight line passing through the first point and the second point may be a first imaginary straight line. The first imaginary straight line may intersect with the third region.

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.