Abstract: The invention relates to a drilling tool (11), comprising a drill shank (22) which has an inner chip space (13) and an outer chip space (14) which extend axially along the drill shank (22) and which in each case accommodate at least one indexable insert (21, 22), the drill shank (12) having a left-hand twist for damping vibrations and increasing the cutting capacity.

Abstract: A medical drill for drilling holes in a bone or cartilage is formed with an end drill section. The end drill section has a specially formed drill tip at the distal end. The drill tip includes a flattened section which is located diametrically in relation to the central axis of the drill. The drill may be formed on the end of a router to provide a single loop to drill a pilot hole and then continue with the routing process. The drill section minimizes the heat created within the bone or cartilage.

Abstract: An end mill (10) has a cylindrical shank (12) with a longitudinal axis (22). Attached to the cylindrical shank (12) is a center flute (14) having a cutting edge (18) extending beyond the longitudinal axis (22). A non-center flute (16) is also attached to the cylindrical shank (12). The center flute (14) has a first rake angle (32) and the non-center flute (16) has a second rake angle (32) not equal to the first axial rake.

Abstract: A percussive blow assisted rotary drill includes an axially extending shank (1) with a leading end face (3) and an axially extending outside surface (2) containing a helically extending drilled material removal groove (4, 5). At least one hard metal cutting plate (6) extends across a diameter of the shank and has a base part fixed in a continuous groove (9) in the leading end face (3) of the shank (1). The base part (10) is reinforced by an outwardly extending projection (12) in at least one of its side surfaces extending across the shank diameter. Preferably, the projections forms a part of a circle and are centered between the opposite ends of the cutting plate. The continuous groove (9) has a recess in at least one of its side surfaces shaped to coincide with the shape of the outward projection (12) on the cutting plate. Accordingly, the base part (10) is secured in a positively locked manner and preferably is centered in the leading end face of the shank.

Abstract: A deburring tool having an insert having four cutting edges such that the tool will cut in either direction of rotation is disclosed. The insert is pivotably mounted on a handle.

Abstract: A method of, and apparatus for, treating an elongate rotary tool that presents a sharp cutting edge are described. The method includes the steps of emitting under pressure from a nozzle an abrasive fluid stream comprising an abrasive grit entrained in a fluid; and impinging the abrasive fluid stream against the sharp cutting edge of the elongate rotary tool for a preselected time so as to transform the sharp cutting edge into a relatively uniformly honed edge. The apparatus includes a rotatable fixture that releasably holds the elongate rotary tool. A nozzle that emits under pressure an abrasive steam. The nozzle and the elongate rotary tool are relatively moveable so that the abrasive stream impinges the entire length of the sharp cutting edge.

Abstract: A tool bit for use in at least one of a drilling and cutting operation is formed of an axially extending carrier member (1) and a cutting member (2). The cutting member (2) has an expansion joint (2a) extending parallel to the axis of the carrier member (1). The expansion joint (2a) is formed by reducing the thickness of the cutting member (2) so that material webs (2b) remain. In the fabrication and formation of the tool bit, the cutting member (2) is a single unit. In the use of the tool bit, due to the expansion joint the cutting member forms individual operating units (2a) affording reduced material expense of the cutting member (2), because of reduced stresses.

Abstract: The invention relates to a rotating shank-type tool (11) with a shank (12), in which at least one main channel (21) for coolant/lubricant extends in the longitudinal direction of the shank and from which, in the end region of the main channel, at least one branch channel (22) leads outward and forms a mouth (23). A cutting head (13) is connected to the shank (12) and has chip grooves (15) and a groove run-out region (16). A sleeve (19) engages over the mouth (23). The end region of the sleeve (19) covers at least the groove run-out region (16) of the cutting head (13). The branch channel mouth (23) is positioned in the shank at a distance from the cutting head (13).

Abstract: An improved self centering spade drill having at least three cutting blades extending radially outward from the center of the drill, the front edge of the blade constituting the cutting portion of the drill, the rear edge of the blade constituting the port end of the drill which are adapted to be received and supported by a drill holder.

Abstract: A chip discharge flute 22 is formed on the side surface of a drill main body 21 to be rotated about an axial line from the tip to the base end of the drill main body 21 and a cutting edge 25 is formed along the intersecting ridge where the wall surface 23 of the chip discharge flute 22 facing to the drill rotational direction thereof intersects with the tip flank 24 of the main body 21.

Abstract: A tool for tapping a container and removing fluid from the container includes a modified bit having a tip configured to bore a hole through a wall of the container, such as an oil filter casing or a tank wall, and a threaded frustoconically-shaped shank configured to engage the wall material defining the hole and to draw the tool into sealing engagement with the wall. A valve assembly is attached to the tip remote end of the modified bit. The valve assembly includes a hex-shaped surface for engaging a drill socket so that the tool can be rotated as it is pressed against the wall. A passageway extends through the shank for communicating fluid from the container, and a valve is located in the valve assembly in communication with the passageway to control fluid flow through the passageway. A cap fits over the valve assembly at the tip remote end of the tool during non-use and when the tool is being used to bore through the wall to protect the tool.

Abstract: A Forstner bit including a cutter having radial major cutting edges, circumferential cutting edges and a shank adapted to be clamped in a chuck. The cutter is threadably attached to the shank by a rear stem of the cutter being accommodated in a threaded hole provided in the shank. The cutter is formed as a monolithic casting fashioned of a precision-casting steel alloy, with the cutter being subjected to additional grinding only along the major cutting edges and the circumferential cutting edges.

Abstract: A drill comprising a holding section, a prismal section receivable by the holding section, and a top-truncated, pyramidal section which is integral with the prismal section, with the prismal section having side faces and side ridges defined by the adjoining two side faces, the top-truncated, pyramidal section having end faces which taper and coverage on the axis of rotation of the drill, end ridges which are defined by meeting of the adjoining two end faces, and a truncated surface extending across the axis of rotation and forming an angle of more than 1.degree. to less than 90.degree. with the cross-section of the prismal section. The end faces and end ridges of the pyramidal section extend from said side faces and side ridges of the prismal section, respectively. Because the apex of the drill is located out of the axis of rotation, it has enhanced cutting performance.

Abstract: A hand-held drilling tool has at least one but preferably two blade structures which project longitudinally from a transverse base member to terminate in a distal end that forms a cutting element. Each blade structure has a pair of blade sections that are joined together along the longitudinal axis and that extend radially therefrom to terminate in lateral edges. Where two blade structures are present, each forms a handle for rotatably operating the other blade structure; where only one blade structure is present, a flattened handle is provided. The blade structures can have different blade widths for drilling differently sized holes. The blade sections may be offset from one another, and wedge-shaped feet may be disposed on the cutting elements. One of the blade structures can have both a bit portion and a shank portion of different widths. A pilot tip may also be provided on the distal ends of the blade structures. The drilling tool is configured for unitary molding from a plastic material.

Abstract: A spade drill bit device including an elongated shaft formed for rotation about a longitudinal axis thereof, and a flattened blade portion at one end of said shaft. The blade portion has generally planar and parallel opposing faces, and defines opposing side edges, and an end cutting edge therebetween. The cutting edge includes a pair of opposing side spurs each having spur tip portions positioned at the lateral extremities of the cutting edge and terminates at the corresponding side edge. A cutting edge triangular-shaped center tip is included axially aligned with the longitudinal axis, and having a distal end extending beyond the side spurs. The center tip is defined by downward edge portions extending away from the distal end. The cutting edge further includes respective converging edge portions extending between and connecting each side spur to the center tip.

Abstract: A flat drill bit having a shaft with an axis of rotation and a flat drill bit head connected to the shaft. The flat drill bit head includes opposing flat front and back faces, left and right edgewalls between the front and back faces, and a bottom endwall connected to the left and right edgewalls. The left and right edgewalls are angled relative to the front and back faces so as to define left and right cutting edges that are parallel to the axis of rotation. The bottom endwall includes left and right sections, each being angled in opposite directions relative to the front and back faces so as to define left and right bottom cutting edges. The bottom endwall of the drill bit head has a rounded shape thereby providing curved left and right bottom cutting edges. In an alternate embodiment the bottom endwall is generally straight, thereby providing straight left and right bottom cutting edges.

Abstract: A cutting tool having a cutting plate with at least one blade and a central axial hole through which a head screw can be used to connect the cutting plate to a holder having an axial bore through its center for receiving the screw and a recess around the bore for receiving a complimentary projection located around the central hole of the cutting plate which is longer than the recess is deep. Alternate embodiments are provided in which the projection is located on the holder and the recess in the face of the cutting plate. In all embodiments, the recess and projection have contacting surfaces which substantially eliminate axial forces on the head screw.

Abstract: A hand operated countersink has a shaft attached at one end to a cutting insert and at the other end to a handle, wherein said cutting insert is substantially of isosceles triangular shape. The insert has at least two cutting edges each disposed along an equal side of the triangle, one of the cutting edges being operative to cut when the shaft is rotated in one direction, and the other cutting edge being operative to cut when the shaft is rotated in the other direction. In a preferred embodiment, the insert has four cutting edges, two disposed along opposite edges of one equal side of the triangle, and two disposed along opposite edges of the other equal side of the triangle.

Abstract: A precision twist drill bit provided with two helical teeth separated by grooves. According to the invention, its diameter is equal to the minimum diameter of the hole to be drilled plus 0.005 mm, the width of the land (3) lies in the range 0.1 mm to 0.2 mm, neither tooth is ahead of the other, the end is ground so that it has two slopes with pits (4) that radiate from the center, the cutting edges (1, 2) of the two pits (4) are symmetrical, and all of the surfaces of the drill bit are polished to within an accuracy of less than 0.1 microns Ra.

Abstract: A kit for reaming the governor bores of used motor vehicle transmissions includes several cutting tools having cutting heads of different diameter. The diameters of the cutting heads are matched to the differing diameters of the governor bores of different transmissions. Each of the cutting heads is generally flat and has two pairs of flat parallel edge faces. The edge faces of the two pairs are normal to but do not intersect one another. Cutting tips project outward from the zones between neighboring edge faces. The kit further includes a guide for the cutting tools, and the guide has a centering element as well as several pairs of holes. The holes of different pairs have differing relative positions which correspond to the differing relative positions of threaded holes in the different transmissions. This allows the guide to be connected to any of the transmissions. The kit also includes several adapters each of which is provided with first and second centering elements.

Abstract: A fluid container draining device for draining fluid from a fluid container, such as an oil filter, in a controlled manner. It has a front threaded screw with a sharpened drill tip. It has an internal channel communicating between an opening at the forward end of the screw and a rear region of the threaded screw. A fluid valve is positioned at the rear region of the screw in fluid connection with the channel. The fluid valve provides fluid flow control between the interior of the fluid container and the outside of the fluid container. The fluid valve has an internally threaded front region which screws into the externally threaded rear region of the screw, and an externally threaded rear region, onto which a fluid evacuation line is to be attached. A turning portion for turning the device into the wall of the container is located on the device.

Abstract: A standard drill bit of any size is arranged so that the end opposite the cutting tip has a opening with a depth and diameter to accept the desired size of the medium, whereupon insertion of the medium is secured by a set screw perpendicular to and at a appropriate distance from the specified end.

Abstract: A cutting tool particularly adapted for machining brittle plastics in which the cutting head has its cutting edges in the first and fourth quadrants of the x-y axes and contained in a common plane on opposite sides of the axis of tool rotation. The cutting edges are on two planar inserts, which can be either integral or separate elements, which meet at the common plane and each of which is relieved or cut away in the opposite quadrant from its own cutting edge to expose the cutting edges of the other. The walls defining the reliefs have 2 or more non-aligned sections forming different angles with the axis of rotation with the steepest angle beginning at the axis and preferably inwardly of the tip of the tool and, overall, exposing not less than a full quadrant of the cutting edge of the other insert while providing cavities and contours which control the movement of the chips and the flow of coolant fluids.

Abstract: Adjacent one end thereof the shank of a back spotfacing tool has therein a transverse slot, and a cutter mounting pin which extends between opposite sides of the slot parallel to the shank axis. A cutter has in one end thereof a U-shaped slot which is inserted removably over the pin to support the cutter for limited pivotal movement about the pin into and out of an operative position in which a flat, external, limit surface formed on the side of the cutter remote from the open end of its U-shaped slot engages the bottom of the slot in the shank to support the cutter for a cutting operation, and to prevent removal of the cutter from the pin. The cutter may be swung manually to an inoperative position in which the open end of its slot is positioned to permit removal of the cutter from the pin, or the replacement thereof over the pin.

Abstract: A multi-purpose arrow shaft assembly tool is provided having several implements capable of being received within a handle. One of the implements is an insert ardor over which point inserts and nock inserts may be placed which the inserts are heated and inserted into the hollow arrow shaft. To aid in preparing the shaft for receipt of the inserts, a facing cutter and a burring tool are also provided. The facing cutter has an arbor which guides the cutting blade of the facing cutter to produce a perpendicular cut relative to the longitudinal axis of the arrow shaft. The burr is housed within the handle so that the interior of the handel serves as a guide when deburring the arrow shaft. A nock adjusting implement is also provided which not only aids in the rotation of a friction fit nock within the nock insert, but also serves to record and transfer the relationship between the groove in the nock and one of the veins so that indexing of one arrow may be transferred to other arrows.

Abstract: A reamer tip including a main cutting edge and a auxiliary cutting edge adjoining the first main cutting edge; and a flank provided in a region of the main and auxiliary cutting edges and including a first inclined flank region having a first back angle of about 7.degree., and a second inclined flank region directly adjoining the auxiliary cutting edge, extending from the auxiliary cutting edge to the first flank region, and having a second back angle substantially smaller than the first back angle.

Abstract: A high speed rotary boring tool has a plurality of cutter inserts evenly spaced around the circumference of a boring bar. Each cutter insert is individually adjustable so that its cutting tip is spaced a desired distance from the tool rotational axis. Each cutter insert is mounted so that its leading face has a zero rake angle in the axial direction, and a negative rake angle in the radial direction. The cutting tip on each insert is defined by two chamfer surfaces on the intersecting edges of the insert leading face, such that each chamfer surface acts as a chip-deflector surface. The boring tool is designed for cutting action during axial feed into the hole and also during axial feed out of the hole.

Abstract: A Drilling tool for metallic materials comprises a holder (1) having an axial clamping slot in which a plate-shaped drilling blade (2) is inserted and clamped against a limb (8) of the clamping slot by means of a threaded pin (3), which is provided with a head (21) and which engages in a bore (15) in the drilling blade (2) and in a bore (12) in said limb (8). The center axis (13) of the limb bore (12) is offset relative to the center axis (24) of the drilling blade bore (15). The mutually facing circumferential edges of the head (21) of the threaded pin and the bore (15) of the drilling blade is bevelled. A centering pin (11) is inserted in the holder (1) and engages in a centering slot (18) in that side (17) of the drilling blade (2), which is contacting the base surface (9) of the clamping slot (4) to center the drilling blade (2) with respect to the rotational axis (6) of the holder (1).

Abstract: Flat drill bit for drilling holes in wood, comprising a plate (12) with two longitudinal sides (16,17), two main radial edges (14,15) and a pilot point with two converging pilot edges (18,19), where main radial edges, pilot edges and short lateral edges (24,26) being short portions of the longitudinal sides all have positive rake angle, produced by grooves parallel to the edges facing forwards during rotation. For larger diameters the pilot point has two converging pilot edges and two parallel sides (27,28).

Abstract: A cylindrical bit is made from an elongated shaft with a spiral blunt pointed cutting element secured to one end by welding or molding. The upper end of the shaft is held in the chuck of a hand-held drill. The drill, battery or mains powered, rotates the shaft. The rotating shaft is repeatedly plunged into the compost mixture to add air and air holes to improve biological decomposition and conversion of organic material into a humus-like mixture (compost).

Abstract: The present invention relates to a drill comprising a shaft with chip-conveying flutes and a drill head with two or more cutting elements. Each of the cutting elements comprises a cutting edge which is delimited between a chip-breaking surface and a relief surface and which, at least in the proximity of the geometrical center or rotational axis of the drill, comprises a curved portion. The cutting edge of the individual cutting elements is located with its curved portion in such a way that a tangential point on a straight line that extends from the central axis and tangentially touches said curved edge portion, is provided distantly from the central axis of the drill. In the immediate proximity of this central axis, the cutting edge is terminated in a small material portion which is common for all cutting edges and which extends between the cutting elements in order to serve for centering the drill.

Abstract: A drilling tool and, in particular, a rock drill for the creation of breaches in concrete or masonry for the use of drill hammers is proposed, which is configured as a cross drill bit having four cutting fins. In order to optimize drilling capacity, the drilling tool is provided with a cross drilling head which merges in one piece into a conveyor spiral matched to the drill head. A purpose-specific cutting element facing serves to optimize the drilling capacity.

Abstract: A bit usable in combination with a rotatory driver, such as a drill, for extracting a remnant of a cut-off pipe from a pipe socket. The bit comprises a forward portion which is a pilot to keep the bit centered in the remnant and thereby centered in the pipe socket, a forward-facing ring cutter whose inner and outer diameters generally match the inner and outer diameters of the pipe remnant being extracted, said ring cutter being operable to cut and/or scrape the remnant edgewise from the socket, and a forward facing ring scraper operable to stop the bit from excessive penetration into the pipe socket and operable to scrape bonding material remnants from the end face of the pipe coupling.

Abstract: A reamer for shaping a socket, such as a hip socket, comprising a cutting head located at one end of a rotatably driven shaft and having a hemispherical portion with a hemispherical exterior surface. The hemispherical portion containing an open substantially hollow chamber and helical openings such as slots, in said hemispherical portion connecting between the exterior surface and the chamber. The trailing portion of each of the openings having a cutting or trailing edge raised slightly above the leading edge of the opening or slot to move material from the socket into the chamber during rotation of the cutting head. The cutting edges having serrations thereon. At least two cutting edges extending across the polar region of the cutting head. A stem extending from the interior center point of the substantially hollow chamber and extending along the polar axis of the hemispherical reamer for connecting and disconnecting the cutting head to a rotatable source.

Abstract: A pipe joint cleaner device primarily for plastic pipes which after being cut are to be joined together comprising an open tapered cone member having a plurality of sharp raised projections on both the exterior face of such cone and on the interior face thereof whereby when a cut piece of pipe is inserted into the interior of the cone, in contact therewith, and relative rotation is induced between the pipe and the cone, any burrs or slivers on the exterior end and surface of such pipe are removed by contact with the projections on the interior face of such cone and, conversely, when the tip of the cone is inserted into a cut piece of pipe until firm contact with the exterior of the cone results and again relative rotation takes place, any burrs or slivers on the inside of such pipe end will be removed by the projections on the exterior face of such cone. Due to the cone shape, the device is substantially self-centering, eliminating the need for complicated jigs or the like.

Abstract: A drill has a pair of cutting edges (4) which are arranged at positions that are substantially uniformly circumferentially spaced about its rotation axis. Each of the cutting edges (4) has a first linear cutting region (4a) and a second linear cutting region (4b) which are aligned with each other on the same straight line, and a curved cutting region (4c) which is located between the first and second linear cutting regions (4a, 4b). The curved cutting region (4c) has a third linear cutting region (4e, 4f) which extends in a direction intersecting with the second linear cutting region (4b) at a prescribed angle. With this structure, it is possible to prevent chip loading etc. which may be caused during perforation drilling operations. In a throw-away tipped drill, a notch (118a) is formed in a received portion of an insert (110) which is mounted on a shank (130). A holding portion (131a, 131b, 133a, 133b) of the shank (130) corresponding to the notch (118a) is provided with a through screw hole (138).

Abstract: A router bit for laterally cutting through sheets of wood product, such as plywood and the like. The bit includes a shank portion adapted to be gripped in the chuck of a router, a fluted portion, and a tip. The fluted portion has two helical left-hand flutes. Each flute has a cutting edge and a web portion having a convex surface that extends rearwardly and immediately inwardly from the cutting edge, without a land, in a continuous curve. The flutes are formed by parabolic grinding. In one embodiment the tip is conical in shape and has two diametrically opposed tip flutes for cutting axially into a workpiece. In another embodiment the tip is flat and the bit is adapted only to cut laterally through the workpiece.

Abstract: The tool for machining bore transitions includes a holder drivable rotatably through at least one rotation, and drivable in an advance stroke and in a return stroke; and a spring wire having at least two resilient arms with overlapping movable free end, the spring wire being bent into a hairpin shape so as to have a stem or bent end portion structured to be inserted and held in the holder and a cutting medium provided on the free ends of the resilient arms for machining the bore transitions. The holder can advantageously be provided with a slot for the stem, threaded bolts which engage between the resilient arms of the spring wire and a spring which spring-loads the side of the spring wire inserted in the slot.

Abstract: A drill of simple construction, using commercially available tips or tips obtained by simply modifying them, well balanced in cutting resistance, and capable of drilling small-diameter holes.A main cutting edge (12) of a center-side cutting edge 1 is situated on a base line VP of a circular cone having its vertex on a point V on a tool central axis OO and a half vertical angle .alpha.. An intermediate cutting edge (2) having a length substantially equal to 1/2 of the length of the main cutting edge (12) is arranged on a straight line V'Q', extending parallel to a base line VQ, which is symmetrical to the base line VP with respect to the tool central axis OO and advanced ahead of the base line VQ for a lip height t mm in the axial direction, so that a straight line connecting the respective middle points of the intermediate cutting edge (2) and the main cutting edge (12) intersect the tool central axis (OO) substantially at right angles.

Abstract: A drill comprising a solid shank with a first, tip-forming end having cutting edges on opposite second end and a number of flutes corresponding to the number of cutting edges. The flutes extend from the tip end towards the other end and have the purpose of forming and conveying chips from the corresponding cutting edge. At a predetermined distance from the tip, each individual flute turns from a first, chip-forming zone with a predetermined width or cross-sectional area into a second, merely chip-conveying zone with a larger width or cross-sectional area. After having been formed in the first zone, the chips are given the possibility of dilating in the second zone, in order to facilitate chip conveyance.

Abstract: A burnishing drill includes a cylindrical shank and a drill body connected to the shank. Drilling edges, first reaming edges and second reaming edges are formed on a first reduced diameter portion, a second reduced-diameter portion and a third reduced-diameter portion respectively located at a foremost end of the drill body. Each of the reaming edges is inclined with respect to the longitudinal axis of the drill at an angle which is set so as to be within a range of between 5.degree. and 30.degree.. During a boring operation using the drill, a hole is drilled by the drilling edges and the drilled hole is then worked by the first reaming edges and the second reaming edges to provide a smooth inner wall in the drilled hole. Since each of the reaming edges is formed to extend radially outward from the foremost end of the drill and incline axially in the rearward direction at a relatively small angle, the centering property can be greatly improved.

Abstract: An improved apparatus for pulling a wire through a pre-drilled hole is detailed. The apparatus comprises a pair of opposing arms which reversibly grasp the wire. The opposing arms are attachable to a rod which is capable of mating with a rod or drill bit. The rod or drill bit is pulled through the hole which, in turn, pulls the wire through the same hole.

Abstract: A cutting insert includes a cutting edge extending obliquely relative to a center line of the insert. A chip breaking recess is spaced inwardly from the cutting edge and extends parallel hereto. A drill tool contains three inserts situated along a common diameter. The center insert has a cutting edge radially overlapping the cutting edges of the other two inserts. Each of the cutting edges of the other two inserts extends axially rearwardly and radially outwardly.

Abstract: This patent discloses a method of manufacturing an insert drill having three or more flutes and a three flute insert drill that may be manufactured by the disclosed method. The method allows accurate machining of insert pockets without requiring removal of a large volume of material from an adjacent flute. The drill disclosed by this patent has three or more cutting inserts which cut chips that are smaller than drills of similar size that have a smaller number of cutting tip inserts. Smaller chips allow easier evacuation of chips and enhance cooling of the drill and workpiece.

Abstract: This invention concerns a pull boring cutter head assembly for machining long bores such as hydraulic cylinders and includes the use of support bearing blocks projecting from the cutter head to support the latter during cutting operations. The blocks are automatically radially adjustable under suitable biasing.

Abstract: A drill bit is provided having a novel drill point for drilling a variety of materials. The drill point comprises at least two opposed cutting edges, the cutting edges forming a predetermined drill point angle. The cutting edges have a first radial component between the extreme tip of the drill point and their respective lands. The first radial component is substantially concave. The cutting edges have a second radial component defined generally where the cutting edge merges with its respective land, the second radial component being substantially convex. The drill point of the invention can be applied to any variety of drill bit or cutting tool having any number of flutes, or may comprise a replaceable drill point. A method is also provided for forming the novel drill point according to the invention.

Abstract: A drilling and chiseling bit includes a base member (1) having an axis extending in the drilling and chiseling direction. The base member has an end face disposed transversely of the axis, with a recess (3) extending in the axially direction inwardly from the end face. A cutting member (2) is secured in the recess by a soldered joint. At least one of the base member and cutting member is formed to prevent the development of shear stress peaks in the end regions of the recess extending transversely of the axial direction. To prevent the shear stress peaks, relief notches or recesses can be provided in the base member (1) or the soldered joint (4) can have a variable thickness in the axial direction increasing towards the opposite ends of the recess.

Abstract: Disclosed are methods for applying durable markings to wearing surfaces, such as concrete factory floors, roadways, terrazzo or ceramic tile floors, or for imparting particular floor surface qualities, such as providing a non-skid surface. A diamond surface drill bit rotating at, for example, 2500 to 5000 rpm is employed to form dry recesses in the surface, which recess is immediately receptive to adhesive for attaching a premolded insert, or to an insert formed in situ, such as an insert of an acrylic polymer. The disclosed surface drill bit has a cutting end with two general types of diamond-impregnated cutting element segments attached. Attached around the periphery of the cutting end are peripheral gauge cutting element segments of arcuate configuration spaced from each other.

Abstract: A cutting insert for a rotary cutting tool comprises a body of tungsten carbide, with layers of polycrystalline diamond on opposite sides of the body. The diamond layers overlap across the centre-line of the insert. The cutting insert is shaped for retention at the end of the rotary cutting tool so that the first and second sides of the cutting insert are substantially parallel to the axis of the cutting tool, and the diamond layers are offset from one another across the width of the body so that they define the lips or major cutting edges of the cutting tool.

Abstract: A tool for cutting an access hole in plasterboard which is mounted to a wall stud. The tool includes a housing portion, a plug or connector portion and a cutting element such as a screw which has a head and a threaded shank. The housing portion has an exit opening, an interior cavity which forms a seat for the head of the cutting portion and a bore which extends from the exit opening to the cavity. The shank of the screw extends freely through the bore and beyond the exit opening. The plug or connector portion of the tool is threaded into the housing and engages the head of the screw for fixing the screw relative to the housing and includes a shank for insertion into the jaw or chuck of a rotary drive mechanism for rotating the cutting element about its central longitudinal axis.