A method for producing a cutting tool with a cutting edge that is formed at least in sections by an end face and a flute comprises the following sequence: Processing of the end face by means of grinding, and polishing of the flute by means of a flute polishing. Here, the flute polishing is carried out by means of a polishing wheel, wherein the polishing wheel is guided during the polishing in such a way that it is moved over the cutting edge and, at least in sections, a final edge rounding on the cutting edge is produced. Further, a cutting tool is disclosed that has been produced according to such a method.

A drill in which: a chip discharge groove is formed in an outer periphery of an edge portion serving as a leading end side portion of a drill body; and a cutting edge is formed in an intersecting edge between a rake surface of a leading end side region and a leading end flank of the edge portion, the drill comprising a margin portion, a shoulder portion and a web thinning portion, wherein: the cutting edge comprises, in order from a rotation center, a first cutting edge portion, a second cutting edge portion, a shoulder cutting edge portion, and a margin cutting edge portion; the honing width gradually decreases from the boundary P1 toward the position P2; and the conditions represented by expression (1): honing width of second cutting edge portion?R1 and expression (2): 2.0<R1/R2<5.0 are satisfied.

In a drill, a negative land 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.

The present invention relates to a drilling tool and method for modifying a blind hole in a blade root insert of a wind turbine. The invention further relates to an apparatus and method for cleaning a blind hole. The method for modifying a blind hole comprises: removing a blade screw located in the blind hole, inserting a drilling tool into the blind hole, fixing the drilling tool in a drill, recessing the blind hole by a predetermined depth, with a maximum diameter of the end section and of the hole bottom after recessing being smaller than or equal to a diameter of the end section prior to recessing and a transition from the end section to the hole bottom being round after recessing, removing the drilling tool and the drill, mounting the blade screw in the modified blind hole.

Provided is a drill insert to ensure sufficient chipping resistance with respect to a large cutting load, which is detachably attached to a distal portion of a drill body which is rotated around an axis, in which a polygon face of a polygonal plate-shaped insert body is a rake face, a side face disposed around the rake face is a flank face, a cutting blade is formed on a ridge portion in which the rake face and the flank face intersect each other, the cutting blade includes a honing face, the honing face includes a first convex curved face continuous with the rake face and a second convex curved face continuous with the flank face, and in a cross section orthogonal to the cutting blade, a curvature radius of the first convex curved face is larger than a curvature radius of the second convex curved face.

In a hard-film-coated drill having a cemented carbide drill body coated with a hard film, the drill body is provided with a smooth region at a boundary between a flank surface and a rake surface. The surface hardness of the hard film is within 2000 to 2500 HV in Vickers hardness. A radius r1 (m) of curvature of the first ridgeline L1 where the smooth region and the flank surface intersect is represented by r1=0.45D+a1 (10a125), where D is the diameter (mm) of the body. A radius r2 (m) of curvature the second ridgeline L2 where the flank surface and a margin intersect is represented by r2=0.65D+a2 (39a267). A thickness t1 (m) of the hard film is represented by t1=0.8ln(D)+a3 (0.7a33.0).

The invention relates to a rotary cutting tool (1), such as a drill (2) or a reamer (3), extending longitudinally along an axis (4) and comprising at least one main cutting edge (5) so that when the tool (1) is rotated about the axis (4), the tool (1) advances axially to perform a cutting operation on a material.

According to the invention, the tool (1) comprises means for braking (7) the axial advance of the tool (1) during the cutting operation.

A cutting element may include a substrate having a non-planar upper surface with a peripheral edge, and an ultrahard layer. The upper surface may include at least one depression formed at least proximate the peripheral edge; and a compressive stress hoop extending around the upper surface adjacent the peripheral edge, extending into the at least one depression, and configured to reduce tensile stress in the ultrahard layer. The ultrahard layer may be on the substrate and may have a non-planar top surface and an interface formed between the ultrahard layer and the substrate.

A cutting element may include a substrate having a non-planar upper surface with a peripheral edge, and an ultrahard layer. The upper surface may include at least one depression formed at least proximate the peripheral edge; and a compressive stress hoop extending around the upper surface adjacent the peripheral edge, extending into the at least one depression, and configured to reduce tensile stress in the ultrahard layer. The ultrahard layer may be on the substrate and may have a non-planar top surface and an interface formed between the ultrahard layer and the substrate.

A drill includes a flank face, a rake face, and a main cutting edge on a ridgeline between the rake face and the flank face. The main cutting edge has a first curved portion having a curved shape contiguous with the flank face and a second curved portion having a curved shape contiguous with the rake face in a sectional view orthogonal to an extending direction of the main cutting edge. A first curvature radius of the first curved portion is larger than a second curvature radius of the second curved portion.