A rotating tool includes a tool body which rotates around an axial line, four or more chip discharge grooves which are formed on an outer periphery of the tool body with gaps therebetween in a circumferential direction, and a plurality of cutting inserts which are arranged in multiple stages along the chip discharge grooves. In a cross-sectional view perpendicular to the axial line, when a center angle formed between a pair of virtual straight lines which connects each of the cutting edges of the cutting inserts disposed in a pair of chip discharge grooves adjacent to each other in the circumferential direction and the axial line to each other is defined as an angle, a plurality of angles formed around the axial line include one maximum angle (max), one minimum angle (min), and two or more angles other than the angle (max) and the angle (min).

Provided is a coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate. The coating layer includes an alternating laminate structure of an alternating laminate of: a first composite nitride layer including a compound having a composition represented by (Ti.sub.xAl.sub.1-x)N (wherein x denotes an atomic ratio of the Ti element based on a total of the Ti element and the Al element and satisfies 0.10x0.35); and a second composite nitride layer including a compound having a composition represented by (Ti.sub.yAl.sub.zM.sub.1-y-z)N (wherein: M denotes an element of at least one kind selected from Zr, Hf, V, Nb, Ta, Cr, Mo, W, Si and Y; y satisfies 0.30y0.90; z satisfies 0.10z0.70; and y and z satisfy y+z1). The first composite nitride layer includes a phase having a lattice constant of from 0.400 nm or more to 0.430 nm or less and a phase having a lattice constant of from 0.755 nm or more to 0.810 nm or less.

A rotary tool comprises a cylindrical sleeve including an opening formed in an outer circumferential surface thereof providing fluid communication between a hollow interior of the sleeve and an environment surrounding the sleeve. The sleeve includes an axially extending flow passage formed therein terminating in a first fluid outlet formed in an open end of the sleeve disposed adjacent a cutting element of the rotary tool. The fluid outlet is configured to deliver a flow of a fluid toward the workpiece to cause chips formed during the machining operation to be directed away from the workpiece and out of the hollow interior of the sleeve through the opening formed in the outer circumferential surface thereof.

A cutting tool according to an aspect of the present disclosure includes a cutting edge portion which contains at least one of cubic boron nitride and polycrystalline diamond. The cutting edge portion includes a flank face, a negative land contiguous to the flank face, and a cutting edge formed by a ridgeline between the flank face and the negative land. At least one of the negative land and the flank face is provided with a plurality of recesses and a projection. The projection is formed by arranging the edges of adjacent recesses in contact with each other.

There is provided a rotary tool including a rotary tool body and a blade provided to the rotary tool body and having a cutting edge, the blade containing 80% by volume or more of diamond, and the blade including a land surface extending along the cutting edge, and a chip breaker having a recess located opposite to the cutting edge with the land surface therebetween.

A rotating tool includes a tool body which rotates around an axial line, four or more chip discharge grooves which are formed on an outer periphery of the tool body with gaps therebetween in a circumferential direction, and a plurality of cutting inserts which are arranged in multiple stages along the chip discharge grooves. In a cross-sectional view perpendicular to the axial line, when a center angle formed between a pair of virtual straight lines which connects each of the cutting edges of the cutting inserts disposed in a pair of chip discharge grooves adjacent to each other in the circumferential direction and the axial line to each other is defined as an angle, a plurality of angles formed around the axial line include one maximum angle (max), one minimum angle (min), and two or more angles other than the angle (max) and the angle (min).

A cutting tool including an annular cutter body having at least one V-shaped pocket formed therein and a cutting tool cartridge configured to be received in the at least one pocket of the cutter body. The cutting tool cartridge including a main body. The main body includes a cutting head having a cutting chip control portion and a pocket configured to receive a cutting insert.

A cutting element for use in a cutting operation, comprising a cutting edge (CE) capable of cutting out material from a workpiece during the operation, to form therein a workpiece corner of angle alpha. There exists at least one view of the cutting edge in which a portion of the cutting edge is delimitable by a first (L1) and a second (L2) line oriented tangentially to the portion of the cutting edge portion at respective tangency points A and B. The lines form therebetween a cutting angle corresponding to the workpiece corner angle alpha and have a vertex 0. For a bisector of the cutting angle intersecting the portion of the cutting edge at the point C, the projection C of the point C of the portion of the cutting edge on a line OL passing through the vertex 0 perpendicularly to the plane of the one view is located between projections A1 and B of the respective points A and B of the portion of the cutting edge on the line OL.

A cutting apparatus can include a cutting insert having at least one chip breaking mechanism. A chip breaking mechanism can include an elliptical hump supported by an inner rib. The elliptical hump can be positioned adjacent a corner of a cutting insert body, for example. The elliptical hump can also be positioned adjacent a tapered cutting edge and a plurality of grooves that include an outer groove and an inner groove that have different radiuses are spaced apart from each other by a lip, or step. Embodiments may also include a variable land positioned adjacent to an outwardly from the outer groove to facilitate chip breaking.