A cutting insert includes an upper surface and upper edge. The upper surface includes a second side part, a first corner part, and a second corner part. The upper surface further includes a first surface and a second surface. The upper edge includes a first edge located at the first corner part, a second edge located at the second side part, and a third edge located at the second corner part. The second surface includes a first region extending toward the first corner part, and a second region extending toward the second corner part. A distance between the first region and the upper edge is smaller at a side of the second edge than at a side of the first edge. A distance between the second region and the upper edge is smaller at a side of the second edge than at a side of the third edge.

A cutting insert according to one embodiment includes: a rake face; a flank face continuous to the rake face; and a cutting edge constituted of a ridgeline between the rake face and the flank face. A coolant flow path is provided inside the cutting insert. One end portion of the coolant flow path opens in the flank face to form a coolant ejection hole. The flank face is provided with a coolant guide groove extending from the coolant ejection hole toward the cutting edge with a base end portion of the coolant guide groove being connected to the coolant ejection hole and with a front end portion of the coolant guide groove being disposed at a position close to the cutting edge relative to the base end portion.

A cutting insert may include a first surface having a polygonal shape, a second surface, a third surface and a cutting edge. The first surface may include a first corner, a first side, a first inclined surface located along the first side, and a second inclined surface located along the second side. In a plan view of the first surface, a width of the first inclined surface in a direction orthogonal to the first side may become larger as approaching the second side. A width of the second inclined surface in a direction orthogonal to the second side may become larger as approaching the first side.

In an embodiment, an insert includes an upper surface including a corner part, a lower surface, a side surface, and a cutting edge. The side surface is between the upper surface and the lower surface. The cutting edge is at least at a part of a first region in which the upper surface intersects with the side surface. The cutting edge includes a first cutting edge at the corner part, a second cutting edge, a third cutting edge, and a fourth cutting edge. The second cutting edge is next to the first cutting edge, and also next to the third cutting edge. The third and fourth cutting edges: each have a convex curvilinear shape with first and second radii of curvature, respectively; and extend downward and upward, respectively, in a side view as going farther from the second cutting edge. The second radius smaller than the first radius.

A swiss turning tool assembly includes an insert and a tool holder. The tool holder includes a head portion which in turn includes an insert pocket and a fastener hole opening out to a flank side of the tool and to a pocket opening in the insert pocket. The insert pocket also includes a tool clamping arrangement which in turn includes a tool base surface and at least one tool abutment surface forming an external acute angle with the tool base surface. The insert includes an insert base surface which in turn includes at least one insert abutment surface forming an internal acute angle with the insert base surface. To achieve a clamped position, a single fastener, accessed from the tool's flank side abuts the insert.

A cutting insert includes a split cutting edge, formed at an intersection of the insert forward surface and the insert upper surface, the split cutting edge includes an axially leading cutting edge and an axially trailing cutting edge. An undercut is located in the insert forward surface and interrupts the split cutting edge at an undercut edge portion that extends between the leading and trailing cutting edges. The undercut edge portion transitions into the axially trailing cutting edge at a straight trailing cutting edge portion of the trailing cutting edge.

A swiss turning tool assembly includes an insert and a tool holder. The tool holder includes a head portion which in turn includes an insert pocket and a fastener hole opening out to a flank side of the tool and to a pocket opening in the insert pocket. The insert pocket also includes a tool clamping arrangement which in turn includes a tool base surface and at least one tool abutment surface forming an external acute angle with the tool base surface. The insert includes an insert base surface which in turn includes at least one insert abutment surface forming an internal acute angle with the insert base surface. To achieve a clamped position, a single fastener, accessed from the tool's flank side abuts the insert.

A cutting insert according to an aspect includes a top surface and a side surface. At least a part of a ridge line where the top surface and the side surface intersects is a cutting edge. The cutting edge includes a first portion located at a corner portion, a second portion adjacent to the first portion, a third portion close to the second portion, a fourth portion close to the third portion, and a fifth portion adjacent to the fourth portion. When viewed from directly above, a curvature radius of the second portion is less than a curvature radius of the first portion, a curvature radius of the third portion is greater than the curvature radius of the first portion, and a curvature radius of the fourth portion is less than the curvature radius of the third portion.

The technical objective of the present invention is to provide a cutting insert cooling device capable of easily mounting a spraying member to a cutting tool while preventing the rotation thereof and eliminating the risk of losing a screw. To this end, the cutting insert cooling device according to the present invention, capable of spraying cooling water toward the cutting insert coupled to the cutting tool, comprises: a head part which forms the terminal end portion of the cutting tool and has a cooling water guide flow path part, and to which the cutting insert is coupled; a spraying member having a cooling water spouting flow path part to spray, toward the cutting insert, the cooling water guided through the cooling water guide flow path part; and an attaching and detaching unit that slides the spraying member to the head part so as to attach and detach the same.

A cutting insert capable of performing groove machining while efficiently fragmenting chip is provided. A cutting insert 10 includes a front cutting edge 111, a pair of side cutting edges 113, a pair of corner cutting edges 112 each connecting the front cutting edge and a corresponding one of the side cutting edges, corner rake surfaces 122 extending from the corner cutting edges 112, and a protrusion part 150 protruding from the corner rake surfaces 122 and provided with a flat boss surface 160 at a leading end. Corner wall surfaces 180 extending from the boss surface 160 toward the corner rake surfaces 122 are formed at the protrusion part 150. At least a part of the corner wall surfaces 180 has a tilt angle of 40? or larger relative to the boss surface 160.