Tool holder has a first section adapted to be connected to a machining center and a tool holding section comprising a bore with a surface defining an inner diameter of the bore. Dispersed around the surface of the bore and at least partially embedded in the surface of the bore is a joining compound having a Young's modulus greater than a Young's modulus of the surface of the bore.

Drilling tools and/or drill bits having notches with buttressed regions and/or notches therewithin to improve notch strength. In some embodiments, the drill/drill bit may comprise a shank comprising a cutting face, the cutting face terminating in a cutting edge. A notch may be formed along the cutting edge, which may be configured to separate chips formed by the drilling tool during operation. A buttressed region may be formed within the notch and may terminate along the cutting edge. The buttressed region may expand a size of the notch in one or more dimensions.

Drilling tools and/or drill bits having notches with buttressed regions and/or notches therewithin to improve notch strength. In some embodiments, the drill/drill bit may comprise a shank comprising a cutting face, the cutting face terminating in a cutting edge. A notch may be formed along the cutting edge, which may be configured to separate chips formed by the drilling tool during operation. A buttressed region may be formed within the notch and may terminate along the cutting edge. The buttressed region may expand a size of the notch in one or more dimensions.

A cutting tool includes a rake face, a flank face, and a cutting edge ridge line connecting the rake face and the flank face. A portion of the rake face and a portion of the flank face adjacent to the cutting edge ridge line are made of a diamond sintered body including diamond grains. A dislocation density in the portion of the flank face is 810.sup.15/m.sup.2 or less. The diamond grains have an average grain size of 0.1 m to 50 m. A content ratio of the diamond grains in the diamond sintered body is 80% by volume to 99% by volume.

A cutting tool according to one aspect of the present disclosure includes a substrate and a diamond layer coating the substrate. A cutting tool according to one aspect of the present disclosure includes a rake face, a flank contiguous to the rake face, and a cutting edge configured by a ridge formed by the rake face and the flank. The rake face has a first rake face and a second rake face located between the first rake face and the flank. The second rake face and a surface of the substrate located on the side of the rake face form a negative angle. The second rake face is formed at the diamond layer.

A turning tool includes: a holder portion; and a cutting edge portion fixed to the holder portion, wherein the cutting edge portion is composed of a synthetic single-crystal diamond, and the cutting edge portion has a nose curvature having a curvature radius of more than or equal to 0.1 mm and less than or equal to 1.2 mm, and the nose curvature satisfies at least one of a condition that a direction of a line of intersection between the rake face and a bisecting cross section of a vertex angle of the nose curvature is within 10 relative to a <110> direction of the synthetic single-crystal diamond, and a condition that the direction of the line of intersection between the rake face and the bisecting cross section of the vertex angle of the nose curvature is within 10 relative to a <100> direction of the synthetic single-crystal diamond.

The present disclosure is directed to a novel hole saw assembly for use with a removable guide or pilot drill bit in which either or both of a cutting device on the hole saw and/or the tip of the removable pilot drill comprise a hard material, such as diamond or tungsten carbide, or another hard material. The novel hole saw assembly is configured to improve the function of keeping the cutting edge of the cutting device properly located during the hole saw cutting or drilling process, especially when cutting or drilling a hole in materials with surfaces that are hard or slippery, such as stone, glass, certain metals or porcelain, or ceramic floor, ceiling or wall tile.

A controller performs a first process of scanning a cylindrical irradiation region including a focused spot of laser light emitted from a laser light emitter to machine a flank face side of a workpiece to manufacture a cutting tool having a plurality of cutting edges arranged in line. In the first process, the controller scans the cylindrical irradiation region along a scanning path that has periodicity and changes a machining depth to form the plurality of cutting edges. The controller further performs a second process of scanning the cylindrical irradiation region including the focused spot of the laser light emitted in a direction different from an irradiation direction of the laser light in the first process to machine a rake face side of the workpiece.

A handheld core drilling device includes a tool receptacle where the tool receptacle has a receiving sleeve and a tool receiving piece disposed in the receiving sleeve. A compression spring arrangement is disposed within the receiving sleeve. Exactly three equally spaced retaining tabs are formed on the receiving sleeve along a circumferential direction and each retaining tab has a respective stop surface that faces the tool receiving piece. Exactly three equally spaced bearing surfaces are formed on the tool receiving piece along a circumference of the tool receiving piece and each bearing surface faces a respective stop surface. Each of the bearing surfaces includes a stud with a stud surface where the stud surfaces in a radial direction are at most half as wide as the bearing surfaces in the radial direction.

The edge portion includes an upper surface, a side surface, and a land surface. The side surface has a front side surface and a pair of lateral side surfaces. An intersection between the land surface and the front side surface forms a front cutting edge. An intersection between the land surface and each of the pair of lateral side surfaces form a corresponding one of a pair of lateral cutting edges. The edge portion contains 80 vol % or more of diamond. A chip breaker recess is provided between the upper surface and the land surface. The surfaces forming the chip breaker recess include a rake face and a breaker wall surface. The upper surface has a front edge portion opposite to the front cutting edge from the chip breaker recess. A pair of protruding portions are provided to extend from the front edge portion toward the front cutting edge.