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.

A cutting insert in a non-limiting aspect of the present disclosure may include an upper surface, a lower surface, a lateral surface and a cutting edge. The upper surface may include a first corner and a first side. The upper surface may further include a rake surface, a bottom surface and a raised surface. The bottom surface may include a first bottom surface and a second bottom surface. The first bottom surface may be located on a bisector of the first corner. The second bottom surface may be located inwardly of the first side. The first bottom surface may be an inclined surface located closer to the lower surface as going away from the first corner. The second bottom surface may be an inclined surface located further away from the lower surface as going away from the first side.

A straight line along the second line segment and a straight line along the fourth line segment form an acute angle. The straight line along the second line segment and the straight line along the third line segment form an obtuse angle. The straight line along the first line segment and the straight line along the fourth line segment form an obtuse angle. Each of the third curved portion and the fourth curved portion is larger in radius of curvature than the first curved portion and larger in radius of curvature than the second curved portion. In a direction perpendicular to the bottom surface, a distance between the top surface and the bottom surface is equal to a distance between the cutting edge and the bottom surface, or is shorter than the distance between the cutting edge and the bottom 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.

The disclosure relates to a method of manufacturing a cutting tool including the steps of: providing a cutting tool blank including a cutting edge, defined by a cross-sectional wedge angle (β). The wedge angle has a variation along the cutting edge, and material is removed from the cutting edge with a constant material removal rate per length unit of the edge, such as to form a corresponding variation of edge rounding along the cutting edge. The disclosure further relates to a cutting tool including the cutting edge defined by the cross-sectional wedge angle having a variation along the cutting edge and wherein the cutting edge has a corresponding variation of edge rounding along the cutting edge.

An assembly of a generally rhombus-shaped reversible cutting insert and a support seat. Each end surface of the cutting insert has a corner abutment surface adjacent each nose cutting edge, at least one inner abutment surface on one side of a lateral plane, and at least one inner abutment surface on the opposite side of the lateral plane, and each corner abutment surface is located closer to a median plane than its adjacent nose cutting edge. In each index position of the cutting insert on the support seat, only one corner abutment surface is in operative contact with one of a plurality of protruding supporting members of the support seat, and only the at least one inner abutment surface located on the opposite side of the lateral plane from the operative corner abutment surface is in contact with the at least one remaining supporting member.

A turning tool cutting insert having an insert face with a rake face includes a primary land extending along a first cutting edge. The primary land includes a first primary land portion adjacent a linear edge portion, and a second primary land portion adjacent a central portion of the corner edge portion. The first primary land portion differs from the second primary land portion. A transitional primary land portion adjoins the first primary land portion and the second primary land portion, and forms a transition between the first primary land portion and the second primary land portion. The transitional primary land portion is arranged only adjacent an outer portion of the corner edge portion. Further, a turning tool including a turning tool cutting insert is disclosed.

A cutting edge includes a nose portion, a first cutting edge portion, and a second cutting edge portion. When a boundary between a first inclined portion and a first breaker portion, a boundary between a first step surface and a second breaker portion, a boundary between a second inclined portion and a third breaker portion, and a boundary between a second step surface and a fourth breaker portion are a first position, a second position, a third position, and a fourth position, respectively, the second position is higher than the first position and the fourth position is higher than the third position in a direction perpendicular to the seating surface, and a distance between the first position and the third position is greater than a distance between the second position and the fourth position in a direction parallel to the seating surface.

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 polygonal cutting blade having a circular arc-shaped groove in a hole includes a blade body composed of an upper surface, a lower surface and a plurality of main side surfaces connecting the upper surface and the lower surface. The blade body has a central hole penetrating through the upper surface and the lower surface, and is centrally symmetrical about a central axis of the central hole. At least one set of positioning side surface comprised of adjacent two of the main side surfaces is provided. An inner surface of the central hole has at least one circular arc-shaped groove fitting with a fastening screw for fixing the cutting blade. The circular arc-shaped groove directly faces toward an intersection of the two main side surfaces of the set of positioning side surface. A groove central axis of the circular arc-shaped groove has an offset distance from the central axis.