A cutting insert capable of performing front-turning and high feed back-turning according to one embodiment includes: an upper surface; a lower surface opposite to the upper surface in a vertical direction; a side portion configured to connect the upper surface and the lower surface; a mounting hole extending through the upper surface and the lower surface; and a plurality of cutting edges formed at edges where the upper surface meets the side portion, wherein the upper surface has one or more cutting corners, the plurality of cutting edges include a major cutting edge and a minor cutting edge extending from the cutting corner, and a representative inclination of the minor cutting edge used for high feed back-turning is greater than a representative inclination of the major cutting edge used for front-turning with respect to a virtual reference plane perpendicular to the vertical direction.

A cutting insert may include an upper surface, a lateral surface, and a cutting edge including a boundary between the upper surface and the lateral surface. The upper surface may include a first rising face that extends upward and a second rising face that is connected to an upper side of the first rising face and extends upward. The first rising face may include a first region that extends along a corner portion and a second region that extends along a side portion. The second rising face may include a third region connected to the first region and a fourth region connected to the second region. An entirety of a boundary between the first region and the third region may be positioned above the cutting edge. A boundary between the second region and the fourth region may include a portion disposed below the cutting edge.

A cutting tool includes a two-way indexable cutting insert clamped in a transversely oriented insert receiving pocket of an insert holder. The insert holder includes a forwardly located insert mounting portion that includes upper and lower jaws which together define the insert receiving pocket having a pocket front opening. The lower jaw includes a pocket lower clamping surface. The upper jaw includes a pocket upper clamping surface which faces mutually towards the pocket lower clamping surface and a pocket stopper surface facing generally towards the pocket front opening. The pocket stopper surface is closer to the pocket lower clamping surface and further from the pocket front opening, than the pocket upper clamping surface. The pocket stopper surface is further from the pocket rear opening than the pocket lower clamping surface.

A turning insert includes a top surface, an opposite bottom surface, and a reference plane located parallel to and between the top and the bottom surfaces. A nose portion includes a convex nose cutting edge, and a first and a second cutting edge. The nose cutting edge connects the first and second cutting edges. The first and second cutting edges form a nose angle of 71-85° relative to each other. The nose portion has a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third convex cutting edge. The fourth cutting edge forms an angle of 10-30° relative to a bisector. The distance from at least a portion of the fourth cutting edge to the reference plane increases at an increasing distance from the nose cutting edge. A second protrusion is arranged between the nose cutting edge and the first protrusion.

A cutting insert having a first end surface, a second end surface, and a peripheral side surface. The peripheral side surface includes a rake surface, a front flank and a first cutting edge located in an intersecting edge between the rake surface and the front flank. The first end surface includes a central surface and a side flank located closer to the front flank as compared to the central surface. An intersecting edge between the central surface and the peripheral side surface serves as a first edge, and an intersecting edge between the side flank and the peripheral side surface serves as a second edge, and an angle formed by the first cutting edge and the first edge serves as a first angle α, and an angle formed by the first cutting edge and the second edge serves as a second angle β, wherein α is smaller than β.

An indexable cutting insert for a cutting tool for material processing machines has a first axis of symmetry, at least one fastening bore passing through the indexable cutting insert parallel or coaxially to this first axis, two groups of main cutting edges, secondary cutting edges and cutting corners having a second axis of symmetry rotationally symmetrically opposite one another. At least the main cutting edges enclose an acute cutting edge angle with a plane oriented orthogonally to the first axis of symmetry. A cutting insert holder holds and fixes an indexable cutting insert. A recess for receiving the indexable cutting insert is on an elongated base body with polygonal cross-section. A support surface for supporting the indexable cutting insert is rotated about the base-body longitudinal axis and tilted about a second axis, a line of intersection between the rotated support surface and a plane perpendicular to the longitudinal axis.

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.

A turning insert includes a top surface, an opposite bottom surface, and a reference plane located parallel to and between the top and the bottom surfaces. A nose portion includes a convex nose cutting edge, and a first and a second cutting edge. The nose cutting edge connects the first and second cutting edges. The first and second cutting edges form a nose angle of 71-85° relative to each other. The nose portion has a third convex cutting edge adjacent to the first cutting edge and a fourth cutting edge adjacent to the third convex cutting edge. The fourth cutting edge forms an angle of 10-30° relative to a bisector. The distance from at least a portion of the fourth cutting edge to the reference plane increases at an increasing distance from the nose cutting edge. A second protrusion is arranged between the nose cutting edge and the first protrusion.

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.

A cutting tool includes a two-way indexable cutting insert clamped in a transversely oriented insert receiving pocket of an insert holder. The insert holder includes a forwardly located insert mounting portion that includes upper and lower jaws which together define the insert receiving pocket having a pocket front opening. The lower jaw includes a pocket lower clamping surface. The upper jaw includes a pocket upper clamping surface which faces mutually towards the pocket lower clamping surface and a pocket stopper surface facing generally towards the pocket front opening. The pocket stopper surface is closer to the pocket lower clamping surface and further from the pocket front opening, than the pocket upper clamping surface. The pocket stopper surface is further from the pocket rear opening than the pocket lower clamping surface.