In a drill, a negative hind is provided on a rake face, and a ridge line at an intersecting position of the negative land and a flank face, a ridge line at an intersecting position of the flank face and a margin, and a ridge line at an intersecting position of the negative land and the margin are convex faces in a longitudinal rectangular cross section. When a curvature radius of the convex face of a first ridge line at the intersecting position of the flank face and the negative land is 1, at curvature radius of the convex face of a second ridge line at the intersecting position of the flank face and the margin is 0.8 to 1.5 times the curvature radius of the first ridge line, and a curvature radius of the convex face of a fourth ridge line at the intersecting position of the negative land and the margin is 1.5 to 3.0 times the curvature radius of the first ridge line.

A rotation mechanism 9 rotates a spindle 2a to which a workpiece 6 is attached. A feed mechanism 8 feeds a cutting edge 4a positioned obliquely relative to a rotation axis of the workpiece 6 in a direction containing a cutting direction component orthogonal to the rotation axis with the cutting edge 4a cutting into the workpiece 6 to machine a surface of the workpiece 6. The cutting edge 4a of a cutting tool 4 has been formed by scanning a cylindrical irradiation region including a focused spot of laser light over a diamond-coated layer of a chip base material.

One example of the present disclosure relates to a coupon. The coupon includes a first surface with a first circular channel and a second surface opposite and parallel to the first surface. The second surface is spaced a distance D0 from the first surface and includes a second circular channel concentric with the first circular channel. The coupon also includes a toroidal portion between the first circular channel and the second circular channel. The toroidal portion includes a rectangular sectional portion.

A cutting tool with a device for the prevention of uncontrolled chip formation which are placed in a specific distance to a cutting edge at a layer of polycrystalline diamond (PCD) or polycrystalline boron nitride (PCBN), and to a manufacturing process for the production of such a cutting tool. The PCD or PCBN layer incorporates the device for the prevention of uncontrolled chip formation as an integral part, and the layer with the device for the prevention of uncontrolled chip formation and the cutting edge are produced by way of an additive procedure, or that the device and the cutting edge are produced by removing material of the PCD or PCBN body by laser or electro-erosion.

A cutting insert includes a base body and a coating layer, and also includes a rake surface, a flank surface, and a cutting edge located along an intersecting ridge therebetween. The rake surface includes an outer peripheral part and a middle part protruded relative to the outer peripheral part. The middle part includes a constraining surface. The outer peripheral part includes a first breaker part, a second breaker part, and the third breaker part adjacent to the constraining surface. The constraining surface is configured by the base body and the coating layer does not exist at the constraining surface. A skewness Rsk of a roughness curve at the constraining surface is −1.5 μm to −0.5 μm. A skewness Rsk at the third breaker part is −0.2 μm or less. The skewness Rsk at the constraining surface is smaller than the skewness Rsk at the third breaker part.

A coated cutting tool has a hard coating on a surface of a base material. The hard coating is a nitride of Al, Cr, and Si in which Al is 50 atom % or more, Cr is 30 atom % or more, and Si is 1 atom % or more and 5 atom % or less. The hard coating contains 0.02 atom % or less of Ar, and the atomic ratio A and the atomic ratio B of nitrogen satisfy the relationship of 1.02≤B/A≤1.10, and a diffraction peak originating from the (111) plane of a face-centered cubic lattice structure shows the maximum intensity. In the cross-sectional observation of the hard coating, the number of droplets having an equivalent circle diameter of 3 μm or more is less than 1 per 100 μm.sup.2. The surface of the hard coating has an arithmetical mean curvature Spc value of 5000 or less.

A surface-coated cutting tool according to the present invention includes a tool body and a hard coating layer including a complex carbonitride layer containing a small amount of chlorine and (Ti.sub.(1-x)Zr.sub.xyHf.sub.x(1-y))(N.sub.(1-z)C.sub.z) (0.10≤x≤0.90, 0<y≤1.0, 0.08<z<0.60), a ZrHf and C content ratios in cycles, a cycle distance between a maximum ZrHf content point and an adjacent minimum ZrHf content point and a cycle distance between a maximum C content point and an adjacent minimum C content point are 5 to 100 nm, an average value of content ratio differences Δx and Δz is 0.02 or more, a distance between the maximum ZrHf content point and the maximum C content point is ⅕ or less of the distance between a maximum content point and a minimum content point of adjacent ZrHf components, and a composition fluctuation structure is 10% or more.

A cutting tool comprises a substrate and an AlTiN layer, the AlTiN layer including a first major surface and a second major surface, the AlTiN layer including a first region having a distance of 0 nm or more and 30 nm or less from the first major surface and having a maximum oxygen content ratio of 30 atomic % or more, a second region having a distance of more than 30 nm and 100 nm or less from the first major surface and having a maximum oxygen content ratio of 5 atomic % or more and less than 30 atomic %, and a third region having a distance exceeding 100 nm from the first major surface and having a maximum oxygen content ratio of less than 5 atomic %.

A cutting tool includes a base material, and a coating film covering the base material in contact with the base material. The base material is a cubic boron nitride sintered material. The coating film is a ceramic. An amount of oxygen in the coating film is less than or equal to 0.040 mass percent.

The invention relates to a cutting tool having at least one cavity arranged in the cutting tool, spaced apart from an outer contour of the cutting tool by a wear layer, wherein a thickness of the wear layer corresponds to a wear limit of the cutting tool, wherein an indicator substance is arranged in the cavity.