Abstract: A drill includes a drill body rotatable about a drill axis, and a cutting portion. The cutting portion includes a first grinding face having first and second chisel edges defining an angle therebetween, and a second grinding face having third and fourth chisel edges defining an angle therebetween, the second grinding face being point-symmetrical with the first grinding face. A first relief face associated with a first cutting edge extends from the first and fourth chisel edges and a second relief face associated with a second cutting edge extends from the second and third chisel edges. A first intersection line is formed where the first and second relief faces meet; a second intersection line is formed where the third and fourth relief faces meet. The first and second intersection lines are spaced apart from an imaginary center line passing through the rotational axis and the first and third relief faces.

Abstract: A rotary cutting tool for slotting and a cutting insert replaceably mounted to such a rotary cutting tool. The cutting insert is mounted to an insert pocket of a tool body of the rotary cutting tool and is pressed by an elastic pressure portion provided in the tool body. The cutting insert has an upper surface, a lower surface and four peripheral side surfaces. The top and lower surfaces have an inclined surface pressed by the elastic pressure portion. When the cutting insert is mounted to the insert pocket, the inclined surface of the upper surface is pressed by the elastic pressure portion. The inclined surface is inclined with respect to a cross section of the cutting insert such that the lower surface and two peripheral side surfaces of the cutting insert are contacted with the insert pocket by pressure of the elastic pressure portion.

Abstract: A SiAlON composite includes a SiAlON phase including ?-SiAlON phase, ?-SiAlON phase and grain boundary phase. The SiAlON composite is prepared from a starting powder mixture including a silicon nitride powder and at least one powder providing aluminum, oxygen, nitrogen, yttrium (Y) and erbium (Er) to the SiAlON composite. The SiAlON composite contains the SiAlON phase of at least 90 vol %, z-value of the ?-SiAlON phase ranges between 0.27 and 0.36 and thermal diffusivity of the SiAlON composite is equal to or greater than 2.4 (mm2/sec) and equal to or less than 5.2 (mm2/sec).

Abstract: A cutting tool assembly includes a shank, a shim, a cutting insert, a clamping lever and a set screw. The shank has an insert pocket with a base wall, a lever receiving portion and a screw hole. The shim is disposed on the base wall of the insert pocket and has a shim bore. The cutting insert is disposed on the upper surface of the shim and has an insert bore. The clamping lever is received in the lever receiving portion and clamps the cutting insert to the insert pocket. The clamping lever has first and second extension portions. The set screw is fastened to the screw hole and has a screw head, a threaded portion and an engaging groove. The engaging groove of the set screw engages the second extension portion. The shim includes an avoiding portion for avoiding an interference with the screw head.

Abstract: A cutting insert has parallel first upper and lower faces, parallel second upper and lower faces, first and second side faces, first and second cutting portions, and first and second mounting grooves. The second upper and lower faces are perpendicular to the first upper and lower faces, respectively. The first and second side faces are located at respective ends of the cutting insert. The first cutting portion has a major cutting edge at an edge between the first upper face and the first side face, while the second cutting portion has a major cutting edge at an edge between the second upper face and the second side face. The first mounting groove curvedly or linearly extends from the first cutting portion oppositely to the second cutting portion, while the second mounting groove curvedly or linearly extends from the second cutting portion oppositely to the first cutting portion.

Abstract: A ceramic material includes of ?-sialon (Si(6-z)AlzOzN(8-z)), polytype 15R, an intergranular phase, and yttrium. The polytype 15R includes twin grains.

Abstract: A cutting tool assembly has a cutter body, a clamp pin, a cutting insert and a set screw. The clamp pin is inserted to the cutter body to secure the cutting insert to an insert pocket. The set screw is fastened to a threaded hole of the cutter body to press the clamp pin toward the insert pocket. A side surface of the cutting insert contacts a side wall of the insert pocket at a first contact portion. A head of the clamp pin contact an inner peripheral surface of a bore of the cutting insert at a second contact portion. The first and second contact portions are located such that a moment acts on the cutting insert toward the base wall of the insert pocket around the first contact portion.

Abstract: A rotary cutting tool for slotting and a cutting insert replaceably mounted to such a rotary cutting tool. The cutting insert is mounted to an insert pocket of a tool body of the rotary cutting tool and is pressed by an elastic pressure portion provided in the tool body. The cutting insert has an upper surface, a lower surface and four peripheral side surfaces. The top and lower surfaces have an inclined surface pressed by the elastic pressure portion. When the cutting insert is mounted to the insert pocket, the inclined surface of the upper surface is pressed by the elastic pressure portion. The inclined surface is inclined with respect to a cross section of the cutting insert such that the lower surface and two peripheral side surfaces of the cutting insert are contacted with the insert pocket by pressure of the elastic pressure portion.

Abstract: A ceramic material includes of ?-sialon (Si(6-z)AlzOzN(8-z)), polytype 15R, an intergranular phase, and yttrium. The polytype 15R includes twin grains.

Abstract: An indexable cutting insert is suitable for vertical and oblique machining. The cutting insert has top and bottom surfaces, first to fourth side surfaces extending between the top and bottom surfaces, and a screw hole passing through the top and bottom surfaces. The top surface has a mounting surface of a flat surface. The top and bottom surfaces are rotationally symmetric with each other. A cutting edge is formed at a junction between the top surface and the adjacent first and second side surfaces. A non-cutting edge is formed at a junction between the top surface and the adjacent third and fourth side surfaces. The first and second side surfaces form an acute angle with a plane extending from the mounting surface of the top surface. The third and fourth side surfaces form an obtuse angle with the plane extending from the mounting surface of the top surface.

Abstract: A double-sided cutting insert for milling which has eight main cutting edges and eight wiper edges. The cutting insert includes top and bottom faces and four side faces. Each side face includes first and second sub-faces inclined with respect to each other. The first sub-face has a main cutting edge adjacent to the top face and a wiper edge adjacent to the bottom face. The second sub-face has a wiper edge adjacent to the top face and a main cutting edge adjacent to the bottom face. The wiper edge of the second sub-face is inclined inwardly relative to the cutting insert with respect to the main cutting edge of the first sub-face. The wiper edge of the first sub-face is inclined inwardly relative to the cutting insert with respect to the main cutting edge of the second sub-face.

Abstract: A cutting insert mountable in an insert pocket of a milling cutter and capable of effectively absorbing a radially outward force during high speed machining and high ramp machining. The cutting insert has a top surface, a bottom surface, peripheral surfaces extending between the top and bottom surfaces, a mounting hole extending through the top surface and the bottom surface, a protrusion portion protruding from the bottom surface, and a pair of lower inclined abutment surfaces formed at opposite edges of the bottom surface. The lower inclined abutment surfaces are inclined in opposite directions toward a pair of opposing peripheral surfaces, outwardly and upwardly relative to the protrusion portion. The protrusion portion extends across the mounting hole and has a lateral surface facing radially outwardly of the milling cutter. The lateral surface selectively contacts or does not contact the insert pocket depending on a revolution speed of the milling cutter.