An indexable drill insert (10) includes a top surface (12), a bottom surface (14), and a plurality of side surfaces (16) adjoining the top surface (12) and the bottom surface (14). A plurality of cutting edges (20) is formed by an intersection of a respective side surface (16) with the top surface (12). One aspect of the invention is that the top surface (12) includes a protruding portion (50) having a backwall (50a) and a segmented portion (52) extending radially outwardly with respect to the protruding portion (50) for effective chip breaking. Another aspect of the invention is that a rake surface (48) has a positive rake angle (RA) that varies along a first cutting edge section (22) of the cutting edge (20) to lower cutting force.

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.

There is provided a cutting insert used for both drilling and turning. The cutting insert includes an insert main body having a front surface and a rear surface, the outline shapes of which are parallelogram shapes, peripheral side surfaces disposed on four sides of the insert main body, cutting edges provided on respective intersecting ridge lines between the front surface and the peripheral side surface and between the rear surface and the peripheral side surface of the insert main body, and a hole provided in the insert main body to incline with respect to the front surface and the rear surface, the hole being usable for attachment.

A cutting tool holder of the present disclosure includes a bar-shaped main body. The main body includes a first pocket to receive a first insert, a second pocket to receive a second insert, a first groove extending from the first pocket, and a second groove extending from the second pocket. The first groove includes a second opening located on a rear side in a rotation direction, and the second groove includes a fourth opening located on a rear side in the rotation direction in a cross section orthogonal to a rotation axis. An angle θ1 formed by the second opening and an outer peripheral surface of the main body is smaller than an angle θ2 formed by the fourth opening and the outer peripheral surface of the main body in a cross section orthogonal to the rotation axis.

A cutting insert has a seating surface, an outer peripheral surface, a top surface, and an attachment hole. The cutting edge includes a curved cutting corner edge portion, a first cutting edge portion, and a second cutting edge portion. The top surface includes a first rake face contiguous to the first cutting edge portion, a second rake face contiguous to the second cutting edge portion, and a third rake face contiguous to the cutting corner edge portion and also contiguous to the first and second rake faces. The third rake face has a first region contiguous to the first rake face and a second region contiguous to the second rake face. The first rake face and the first region each have a rake angle which is a positive angle. The second rake face and the second region each have a rake angle which is a negative angle.

A rotary cutting tool is provided having a body and a fluid passage. The body has a shank portion and a cutting portion. The body extends lengthwise along a central axis between a shank end and a cutting end. The cutting portion includes a fluted section and a plurality of teeth extending axially outwardly from the fluted section at the cutting end. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to the cutting end. The internal cavity is defined by an interior wall surface. The cutting portion includes a plurality of channels disposed within the interior wall surface and open to the internal cavity. The fluid passage extends through the shank portion to the internal cavity.

A rotary cutting tool having a lengthwise extending central axis is provided. The tool includes a shank portion and a cutting portion. The cutting portion is connected to the shank portion, and includes a fluted section and a plurality of teeth. The fluted section includes a plurality of flutes disposed within an exterior surface of the fluted section. The cutting portion includes an internal cavity disposed within the fluted section and open to a cutting end. Each tooth includes a front side surface, an exterior side surface, an interior side surface, and an axial end surface. The front side surface intersects with the axial end surface to form an axial end cutting edge that extends radially between an outer radial tip and an inner radial tip, and the outer radial tip is disposed axially outside of the inner radial tip.

A rotary cutting tool cutting insert is provided that includes front, aft, exterior, and interior side surfaces, an axial end surface, and a base surface. The exterior side surface intersects with the front side surface. The interior side surface intersects with the front side surface. The axial end side surface intersects with the front side surface at an axial end cutting edge, with the exterior side surface at a first outer axial edge, and with the interior side surface at a second outer axial edge. The base surface intersects the front, exterior, and interior side surfaces and the aft surface. The base surface intersects the front side surface at an inner edge. An outer radial tip is disposed at a first heightwise distance from an inner edge, and an inner radial tip is disposed at a second heightwise distance from the inner edge.

An indexable drill insert (10) includes a top surface (12), a bottom surface (14), and a plurality of side surfaces (16) adjoining the top surface (12) and the bottom surface (14). A plurality of cutting edges (20) is formed by an intersection of a respective side surface (16) with the top surface (12). One aspect of the invention is that the top surface (12) includes a protruding portion (50) having a backwall (50a) and a segmented portion (52) extending radially outwardly with respect to the protruding portion (50) for effective chip breaking. Another aspect of the invention is that a rake surface (48) has a positive rake angle (RA) that varies along a first cutting edge section (22) of the cutting edge (20) to lower cutting force.

A cutting insert (112) comprising a top surface (118), a bottom surface (120), and side surfaces (122) spanning there-between, said side surfaces (122) comprising one or more feed-facing side surfaces (122a) and one or more radial-facing side surfaces (122b). The top surface (118) is formed with one or more linear grooves, each constituting a chip breaker (125) and being disposed parallel to and adjacent one of said feed-facing side surfaces (122a). The chip breaker (125) is characterised by a constant profile along the entire length of its respective feed-facing surface (122a). Each of said feed-facing side surfaces (122a) is disposed at an acute feed-angle ( feed) with respect to the top surface (118), and each of said radial-facing side surfaces (122b) being disposed at an acute radial-angle ( radial) with respect to the top surface (118), the feed-angle ( feed) being greater than said radial-angle ( radial).