A cutting tool according to an aspect of the present disclosure includes a shank, a joint, and a cutting portion attached through the joint to the shank. The cutting portion includes a core and a surface portion. The surface portion is disposed around a central axis of the cutting portion to cover an outer circumferential surface of the core. The surface portion includes a cutting edge. The cutting edge is disposed on an outer circumferential surface of the surface portion and formed in a helical shape about the central axis. The surface portion is a composite sintered material including a hard phase formed of a plurality of diamond particles and a plurality of cubic boron nitride particles, and a binder phase forming the remainder.

A diamond-coated tool includes: a substrate; and a diamond layer that coats the substrate, wherein the diamond layer includes a first region that is in contact with the substrate, the first region includes a region S1 surrounded by an interface P between the substrate and the diamond layer and an imaginary plane V1 separated from the interface P by a distance of 2 m, and the region S1 has crystal grains grown in random directions.

[Problem] To protect a leading end part of a drill having a coolant hole which is adapted for drilling a thin diameter or very thin diameter hole in a workpiece.

[Solution] A coolant hole 33 is formed in a shank 3 and a shaft body 7 so as to extend through from a rear end surface 31 of the shank 3 to a leading end surface 15 of the shaft body 7 along an axis thereof. A leading end part of the coolant hole 33 is branched into a pair of discharge holes 35, at a position slightly toward a base end relative to the leading end surface 15 of the shaft body 13. The discharge holes 35 extend in the opposite directions, perpendicular to the coolant hole 33, respectively, and open at opposite side surfaces 37, 37 to define discharge ports 39, 39. A leading end opening 41 of the coolant hole 33 is closed by a bottom face 17 of the drill part 9.

A method for machining grooves in the surface of a workpiece in which a dummy groove is machined in the surface of the workpiece by moving a cutting tool relative to the workpiece in a first machining direction of the workpiece, then orienting the cutting tool 180 degrees as compared to the first machining, and subsequently second machining the dummy groove by moving the cutting tool in a second direction opposite to the first direction. A displacement of a cutting edge of the cutting tool, caused by the first and second machining of the dummy groove is measured. A groove is machined with the cutting tool in a forward stroke and then a return stoke with the cutting tool rotated 180 degrees between the strokes. A relative position between the workpiece and the cutting tool during the forward and return strokes is corrected so as to eliminate the displacement.

To provide a method for forming an anchor hole and a diameter expansion device by which a centrifugal force can be appropriately adjusted when a cutting-blade portion is moved in a radial direction by the centrifugal force to grind a diameter expansion portion. In a method for forming an anchor hole for a post-installed anchor in which a diameter expansion drill bit is inserted and rotated in a prepared-hole portion bored in a concrete fixing body and a cutting-blade portion of the diameter expansion drill bit is moved in a radial direction by a centrifugal force to grind a part of the prepared-hole portion to form a diameter expansion portion, the minimum value of the centrifugal force applied to grind the diameter expansion portion is 0.75 N and preferably 1.1 N.

According to the present disclosure, a coated member is provided with a base material and a diamond layer located on the base material. When a ratio (SP3/SP2) obtainable from an SP3 peak derived from diamond crystals measurable by Raman spectroscopy and an SP2 peak derived from a graphite phase is referred to as an SP3 ratio, an SP3 ratio at a first measuring point with a thickness up to 1 m extending from an interface of the base material and the diamond layer toward the diamond layer is higher than an SP3 ratio at a second measuring point that is intermediate in a thickness direction of the diamond layer.

A composite diamond body includes a diamond base material and a stable layer disposed on the diamond base material. The stable layer may have a thickness of 0.001 m or more and less than 10 m, and may include a plurality of layers. A composite diamond tool includes the composite diamond body. There are thus provided highly wear-resistant composite diamond body and composite diamond tool that are even applicable to mirror-finish planarization of a workpiece which reacts with diamond to cause the diamond to wear.

A method for providing a textured surface finish to a substrate includes providing an image having a contrast ratio; altering the image to increase the contrast ratio; determining an engraving profile for an ink transfer tool based on the contrast ratio of the image; etching the ink transfer tool in accordance with the engraving profile; coating the ink transfer tool with an ink; transferring the ink from the ink transfer tool to a substrate; applying a top coat to the substrate while the ink is set; and curing the ink and top coat on the substrate in an oven. The etching creates a plurality of wells in the ink transfer tool for holding the ink. The engraving profile is not identical to the altered image.

A cutting tool comprises a tool body having a first end and a second end, and a longitudinal axis extending between the first end and the second end. The first end comprises two or more cutting portions, with each of the cutting portions comprising a cutting edge and a flank surface. Each cutting edge extends radially outwardly from a centre region of the first end to a perimetral edge of the first end, with the cutting edge being angled relative to the longitudinal axis. Each flank surface extends circumferentially from the cutting edge. Each of at least two of the two or more flank surfaces comprises an abrasive portion extending over at least a part of the respective flank surface and each abrasive portion comprises a plurality of abrasive features.

To provide a tool that ensures improved durability even when a diamond coating containing boron is formed. A diamond coating (40) includes a first layer (41) that is formed as a layer on a surface layer side of the diamond coating (40) and is regarded as containing no boron, and a second layer (42) positioned on a side of a base material (30) with respect to the first layer (41) and contains at least 1000 ppm or more of the boron. Since the first layer (41) with a larger compressive stress is formed on the surface layer of the diamond coating (40), a crack generation from the surface layer side of the diamond coating (40) during the process can be reduced. Consequently, the durability of a tool (1) can be improved even when the diamond coating (40) containing 1,000 ppm or more of boron is formed.