A cutting tool includes a substrate and a diamond layer that covers the substrate. The diamond layer includes a rake face and a flank continuous to the rake face. A ridgeline between the rake face and the flank forms a cutting edge. The substrate includes a top surface opposed to the rake face. When viewed in a direction perpendicular to the top surface, the rake face includes a plurality of protrusions. In a cross-section perpendicular to a direction of extension of the cutting edge, each of the plurality of protrusions includes an inclined portion and a curvature portion continuous to the inclined portion. In the cross-section, a height of the inclined portion in the direction perpendicular to the top surface increases as a distance from the cutting edge increases.

A parting/grooving insert and a method of grinding a parting/grooving insert including rotating a plane grinding surface having a normal vector parallel to the axis of rotation and a tangential direction of rotation; providing a parting/grooving insert including a rake surface, a main clearance surface, and a main cutting edge formed between the rake and main clearance surfaces; orienting/positioning the insert relative to the grinding surface, such that the main clearance surface is parallel to the grinding surface, the normal vector of the main cutting edge being in the plane of the main clearance surface and with a vector component in the direction of rotation forming an angle to the tangential direction of rotation at the insert of at least 20 degrees from parallel orientation; and grinding the main clearance surface to provide grinding marks having an angle to the normal vector of the main cutting edge corresponding to the angle to the tangential direction of rotation.

A turning tool for internal turning of a metal work piece having a rear end, an opposite forward end and a longitudinal center axis extending therebetween. The first nose cutting edge includes a first radially distal point having an associated first rake face and separates and connects a first forward cutting edge and a first rearward cutting edge. A second nose cutting edge of the turning tool includes a second radially distal point having an associated second rake face and separates and connects a second forward cutting edge and a second rearward cutting edge. The second radially distal point is positioned ahead of the first radially distal point. The first forward cutting edge forms an acute first entering angle, the second forward cutting edge forms an obtuse second back clearance angle, and the second rearward cutting edge forms an acute second entering angle.

A parting/grooving insert and a method of grinding a parting/grooving insert including rotating a plane grinding surface having a normal vector parallel to the axis of rotation and a tangential direction of rotation; providing a parting/grooving insert including a rake surface, a main clearance surface, and a main cutting edge formed between the rake and main clearance surfaces; orienting/positioning the insert relative to the grinding surface, such that the main clearance surface is parallel to the grinding surface, the normal vector of the main cutting edge being in the plane of the main clearance surface and with a vector component in the direction of rotation forming an angle to the tangential direction of rotation at the insert of at least 20 degrees from parallel orientation; and grinding the main clearance surface to provide grinding marks having an angle to the normal vector of the main cutting edge corresponding to the angle to the tangential direction of rotation.

In accordance with various illustrative embodiments of the present disclosure, a rotationally symmetric surface of a workpiece is machined by a turning apparatus, wherein the workpiece is rotationally driven around a rotational axis, a cutting tool with a cutting edge positioned at the edge of a rake face is arranged relative to the workpiece, the cutting tool is brought into contact with the workpiece, and the cutting tool is advanced relative to the workpiece along a feed direction parallel to the rotational axis, the normal to the rake face being tilted relative to the feed direction, a first axis and a second axis, the first axis and the second axis are perpendicular to the feed direction and perpendicular to each other.

A method for the laser-based generation of a structure on a rake face of a cutting tool is disclosed, where at least one structure is formed by lines that are generated with a mutual spacing of at most 400 m with a laser beam at least in areas within a predetermined contour on at least one rake face of the cutting tool. A course of the lines forming the structure is oriented with respect to a profile of at least one cutting edge of the at least one rake face.

A cutting part (1) for a tool head (2) for a lathe (3) for machining a workpiece (4), having a cutting edge (5) for removing material from the workpiece (4) and having a rake face (6) for guiding away the removed material or cuttings. The problem of providing a cutting part (1) which can be realized in a simple manner and with which lead-free materials can also be machined is solved in that a flat structure (7) is formed in the rake face (6) of the cutting part (1) adjoining the cutting edge (5) for breaking the cuttings. A lathe (3) for machining a workpiece (4), having a tool head (2) is provided with at least one such cutting part (1).

A cutting tool 1 includes a cutting edge 2, a rake face 4 and a flank 5 and is used for cutting a surface of a cylindrical or columnar work W by a skiving process. The cutting tool 1 is configured to satisfy a relational expression:
tan.sup.1(cos /cos()tan.sup.1(cos.sup.1(r/r))<90
where denotes a rake angle, denotes an inclination angle of the cutting edge 2 with respect to the rotation axis A, denotes an angle between a feed direction of the cutting tool 1 and a direction orthogonal to a rotation axis A in a plane view of the cutting tool 1 and the work W, r denotes a radius of an outer circumferential surface of the work W before processing, and r denotes the radius of the outer circumferential surface of the work W after processing.

A cutting edge of a machining tool and a surface treatment method for the same. A cutting edge of a machining tool and a region in the vicinity of the cutting edge, e.g. a region of at least 1 mm and preferably at least 5 mm from the cutting edge, are defined as a treatment region; and substantially spherical injection granules having a median diameter of 1 to 20 m are injected onto the treatment region with an injection pressure of 0.01 MPa to 0.7 MPa in order for dimples having an equivalent diameter of 1 to 18 m and preferably 1 to 12 m, and a depth at least equal to 0.02 m and at most equal to 1.0 m to be formed such that the projected surface area of the dimples is at least equal to 30% of the surface area of the treatment region.

A method for designing a cutting edge of a cutting element configured for removing material from a workpiece to leave therein a desired end profile (B22,B24,B26). The method comprises the steps of modeling a desired end profile (B22,B24,B26) of the workpiece, the profile having a longitudinal axis and being defined by a bottom surface (B12), a side surface (B16) and an adjustment surface (B14) extending therebetween; defining a lead profile plane (RP.sub.L) and an trail profile plane (RP.sub.T) spaced therefrom, each of the planes being oriented perpendicular to the longitudinal axis; determining a profile contour defined by the intersection line between the end profile (B22,B24,B26) and the lead profile plane (RP.sub.L). The contour profile includes a bottom contour, an adjoining contour and a side contour defined as the intersection lines between the lead profile plane (RP.sub.L) and the bottom surface (B12), the adjustment surface (B14) and the side surface (B16) respectively; designing a rake surface and a relief surface, the intersection line between which defines a cutting edge lying in the adjoining surface (B14) and spanning between the lead profile plane (RP.sub.L) and the trail profile plane (RP.sub.T). The cutting edge is designed such that in any reference plane (RP; FIG. 6A) oriented perpendicularly to the cutting edge, the intersection between each of the rake surface and the relief surface with the reference plane (RP) defines a respective rake line (RK; FIG. 7) and relief line (RF; FIG. 7), the angle (.sub.B) between the lines RK,RF) being equal to or smaller than a similar angle (.sub.B) taken along each of a plurality of similar reference planes (RP) disposed between the reference plane (RP.sub.n) and the lead profile plane (RP.sub.L).