Abstract: A drill is capable of forcibly aspirating and discharging chips to prevent environmental contamination as well as to simplify cleaning the chips. The drill has an intake hole and an opening formed therein so that the aspiration takes place through the intake hole and the chips generated in the cutting process can forcibly be aspirated from the opening. Because the chips can be discharged without using cutting fluid, the drill is useful for preventing environmental contamination. Moreover, as the chips are forcibly aspirated from the opening and discharged through the intake hole, the chips are not scattered around a workpiece under the cutting process and cleaning the chips can become simple and easy.

Abstract: A thread forming tap having a complete thread portion, formed with a predetermined back taper with that decreases rotational torque during tapping work, which reduces load acting on first complete protruding portions, formed at an extreme leading end of the complete thread portion, and thereby suppressing degradation in service life of the tool due to wear.

Abstract: A drill in which a flute is formed from a point to a base end side of a body of the drill, on a side face to be rotated about an axis, a cutting edge is formed between a wall surface of the flute which faces a drill rotational direction side and a flank at the point of the body, and a thinned portion is provided to a web portion of the point. The cutting edge is formed in a convex arc shape with a curvature radius 0.25 to 1 times a drill diameter; a radial rake angle at an outer peripheral portion of the cutting edge is ?60 to ?15 degrees; a corner portion, closer to the center of the point, of the thinned portion is formed in an arc shape with a curvature radius of at least 0.1 mm and not greater than 0.05 times the drill diameter; and the drill includes three flutes and three cutting edges.

Abstract: A cutting edge portion intermediate form that is a pre-sintered body of the cutting edge portion and a supporting portion intermediate form that is a fully sintered body of the supporting portion are manufactured separately. Full sintering is then performed where front end portion of the supporting portion intermediate form is inserted into an insertion hole of the cutting edge portion intermediate form. During sintering, cobalt particles in powdered materials are converted into a liquid phase, and contracting occurs. Because the supporting portion intermediate form has already been fully sintered, only the cutting edge portion intermediate form contracts. The front end portion of the supporting portion intermediate form is squeezed by the cutting edge portion intermediate form. The carbide tip is therefore created in which the cutting edge portion and the supporting portion are strongly bonded.

Abstract: A neck portion grinding apparatus and method is designed to reduce working man-hours and to improve processing accuracy with respect to a processing of a workpiece. The neck portion grinding apparatus includes a grinding device having a disc-like grinding wheel and a wheel rotating device for rotating the grinding wheel, and a machine tool having a main shaft for rotatably supporting a rotating tool and a table mounting the grinding device thereon, and relatively moving the main shaft and the table by numeral control. A shape of a neck portion of the rotating tool can be changed by relatively moving the main shaft and the table while mutually rotating the rotating tool and the grinding wheel, and grinding the rotating tool by the grinding wheel.

Abstract: A shrink-fit tool unit increases the transmission force of rotary power and also improves workability when inserting the rotary tool into the tool holder. A tool holder and a rotary tool to be used for the shrink-fit tool unit are also disclosed. Since a first engaging part and a second engaging part are configured to engage with each other simply by inserting a cylindrical terminal area of a rotary tool, typically, a thread forming tap, into a chuck of the tool holder, even when the machining load receiving from a work piece act both in forward and reverse directions relative to the circumferential direction, it is possible to increase the transmission of rotary power.

Abstract: A helical flute has a constant lead part and a gradually increased lead part. The constant lead part has an axial length ranging from 0.3×LA to 1.2×LA and includes at least entirety of a leading part, so that the cutting performance of a cutting edge at the leading part and shape of chips (curled shape, etc.) are stable. In the constant lead part, because a lead is the smallest and a helix angle is large, a rake angle of the cutting edge is large, so that an excellent cutting quality is obtained and the chips become curled well. Meanwhile, in the gradually increased lead part, because of the lead gradually increased toward a shank, the chips are rapidly discharged toward the shank.

Abstract: A tap is designed so that the pollution of the environment can be prevented and the cleaning can be simplified. The tap includes an intake hole having openings at a screw portion of the tap. Air intake is performed through the intake hole, so that the chips generated by the screw portion in the cutting can be aspirated from the openings forcibly. Because the chips can be discharged without using cutting fluids, pollution of the environment can be prevented. Because the chips can be aspirated from the openings and discharged from the intake hole of the tap, the chips are not scattered on the work piece, and thus a cleaning process of the work piece can be simplified.

Abstract: A drill achieves a long tool life while improving a property for discharging chips. The drill includes: a columnar body which is rotated about an axis; a plurality of cutting edges each being formed at a tip end portion of the body; and a plurality of thinning edges each being formed in conjunction with the cutting edge nearer the axis by providing thinnings at the tip end portion of the body. At least one of the plurality of thinning edges is provided with a concave portion that is formed by cutting the thinning edge to be recessed in a semicircular shape toward the rear side in the rotational direction, and a center of the semicircular-shaped concave portion is provided on a line extended from the tip end portion of the thinning edge when viewed from a tip end direction of the body.

Abstract: A shank has a mount reference surface formed with a mount seat having a mount seat surface inclined at a given inclined angle ?. A diamond raw material is held on the shank in an attitude such that a first bottom surface thereof is in tight contact with the mount seat surface, and a first apex is protruded forward nearly along a centerline of the shank. A portion of the first apex, protruding from the mount reference surface, is ground and removed as a given inclined angle ?. This causes a surface or its vicinity (in a value less thank approximately ±1°) to be formed as a raked face. The first bottom surface of the diamond raw material is held intact in tight contact with the mount seat surface to be integrally bonded thereto by active metal brazing, easily ensuring an increased bonding surface area to easily obtain increased bonding strength.

Abstract: In a semi-finishing cutter, rectangular tips and square tips are disposed in a staggered pattern in an axial direction in second to fourth step portions, so a single cutting edge is formed by a pair of one of the rectangular tips tips and one of the square tips. It is therefore possible to effectively reduce a frequency of contact with a blade root. A cutting speed of the semi-finishing cutter may be increased and a cutting feed may be made faster, so work in a semi-finishing process may be performed efficiently. The rectangular tips and the square tips have simple shapes, so known commercially available throwaway tips may be used. Accordingly, it is possible to provide the semi-finishing cutter in an easy-to-use form without increasing the cost.

Abstract: A spline rolling tool including a plurality of forming teeth that are to bite into a cylindrical workpiece so as to roll splines in the workpiece. Each of the forming teeth has an incomplete toothed region in which a crest of each forming tooth is removed such that an upper end of each forming tooth in the incomplete toothed region is defined by an incomplete-toothed region surface that includes a curved surface portion, a flat surface portion and a slant surface portion. The incomplete-toothed region surface is defined at its periphery by a chamfered edge that has a surface roughness of not larger than about 3.2 ?m. Also disclosed is a process of manufacturing the spline rolling tool, which includes a chamfering step of forming the chamfered edge by using a wire brush having abrasive grains that are fixed to bristles of the wire brush.

Abstract: A cutting insert is provided with at least a circular-arc blade cutting edge as a cutting edge in the form of a substantially quarter circular arc, at an intersection between a rake face and a flank face, and an outer cutting edge extending from one end portion of the circular-arc cutting edge. The rake face is formed so as to be convex in a direction of rotation when the cutting insert is mounted on a tool body. On a section perpendicular to the cutting edge, the rake face is inclined so as to become gentler with distance from the circular-arc cutting edge or outer cutting edge. The circular-arc cutting edge is formed to be convex in the direction of rotation. The outer cutting edge is formed so that its edge ridge line is substantially parallel to the axis of the tool body.

Abstract: A following margin of a following flank of an external thread is shifted more in a screw-rotation direction than a leading margin of a leading flank. Thus, during biting, the following margin bites first, thereby suppressing a force that pushes back a tap and reducing a tapping torque. Because margin portions can be disposed parallel to an axis of a thread forming tap, working is easy and manufacture can be performed inexpensively. When, in forming an external thread by grinding by a grinding abrasive, an inclination angle of the axis of a tap blank and an abrasive axis of the grinding abrasive is equal to a lead angle of the external thread, the margins are formed symmetrically across a root. On the other hand, if the inclination angle is made greater than the lead angle, the following margin can be shifted in the screw-rotation direction, enabling manufacture to be performed as easily and inexpensively as in a conventional case.

Abstract: A drill including a columnar body that is rotated about an axis, a cutting edge that is formed at the tip end of the body, and a thinning edge that is formed continuously with the cutting edge close to the axis of the body, by having a thinning at the tip end of the body. The thinning edge is formed such that a rake angle of the thinning edge relative to the axis of the body changes depending on a location of the thinning edge, where the rake angle of the thinning edge close to the cutting edge is a positive angle larger than that close to the axis of the body.

Abstract: A drill having a web which is provided by a central portion of a cylindrical main body of the drill and which includes a back-tapered portion and a constant-thickness portion. The cylindrical main body has a large diameter portion and a small diameter portion contiguous to the large diameter portion, such that a step is provided between the large and small diameter portions. The large diameter portion provided by the axially distal end portion of the cylindrical main body has an axial length which is larger than an axial length of the back tapered portion of the web provided by the axially distal end portion of the web, such that a boundary between the back-tapered portion and the constant-thickness portion of the web is located in the large diameter portion of the cylindrical main body.

Abstract: A hard multilayer coating including: (a) a backing layer which is to be disposed on a body and which includes a TiAlN layer and a TiAlN+CrN mixture layer that are alternately superposed on each other; and (b) a CrN layer which is disposed on the backing layer and which provides an outer surface of the hard multilayer coating. The hard multilayer coating may further includes (c) an intermediate layer which is interposed between the backing layer and the CrN layer. Also disclosed is a hard multilayer coated tool including a tool substrate as the body which is coated with the hard multilayer coating.

Abstract: A radius endmill has a peripheral cutting edge, a bottom cutting edge, and a rounded corner cutting edges whose ridge line is defined by a circular arc having a given radius as measured in a side view of the endmill that is parallel to the axis. The rounded corner cutting edge is located in a corner portion of the endmill in which the outer peripheral and the axial end intersect each other such that the peripheral cutting edge and the bottom cutting edge are connected to each other through the rounded corner cutting edge. The bottom cutting edge has a radially inner end lying at the axis, and a radially outer end at which the bottom cutting edge is connected to the rounded corner cutting edge. The bottom cutting edge is curved such that its ridge line is defined by a circular arc as seen in a plan view of the endmill that is perpendicular to the axis.

Abstract: A ball endmill having (a) a cylindrical tool body and (b) ball-nosed end cutting edges each of which includes (b-1) a first portion, (b-2) a second portion and (b-3) a third portion. The first portion is defined by a circular arc which is convex in a direction of rotation of the tool body and which has a first radius of curvature as measured in a distal end view perpendicular to the axis. The second portion is defined by a straight line or a circular arc which is convex in the rotation direction and which has a second radius of curvature as measured in the distal end view. The third portion is defined by a circular arc which is convex in the rotation direction and which has a third radius of curvature as measured in the distal end view. The second radius of curvature is larger than the first radius of curvature. The third radius of curvature is smaller than the second radius of curvature.

Abstract: A hard multilayer coating that is to be disposed on a body, including: (a) a first coating layer disposed to be held in contact with the body, the first coating layer consisting of TiAlCrX1-aNa (wherein “X” represents carbon or oxygen, and “a” represents a mixed crystal ratio satisfying 0.5?a?1); (b) a second coating layer disposed on the first coating layer, the second coating layer being provided by a mixture layer consisting of TiAlCrX1-bNb (wherein “b” represents a mixed crystal ratio satisfying 0.5?b?1) and TiAl(SiC)X1-cNc (wherein “c” represents a mixed crystal ratio satisfying 0.