Abstract: Method for manufacturing endodontic instruments having either helical or non-helical flutes. A method is provided for forming superelastic endodontic instruments having helical flutes, wherein a wire of superelastic material is formed into an instrument blank, and before twisting, the superelastic alloy is brought to an annealed state comprising a phase structure including a rhombohedral phase alone or in combination with austenite and/or martensite, or a combination of martensite and austenite. In this annealed state, the instrument blank is twisted at low temperature, for example less than about 100° C., and advantageously at ambient temperature to the final desired twisted configuration. The twisted instrument is then heat treated and rapidly quenched to a superelastic condition.

Abstract: Method for manufacturing endodontic instruments having either helical or non-helical flutes. A method is provided for forming superelastic endodontic instruments having helical flutes, wherein a wire of superelastic material is formed into an instrument blank, and before twisting, the superelastic alloy is brought to an annealed state comprising a phase structure including a rhombohedral phase alone or in combination with austenite and/or martensite, or a combination of martensite and austenite. In this annealed state, the instrument blank is twisted at low temperature, for example less than about 100° C., and advantageously at ambient temperature to the final desired twisted configuration. The twisted instrument is then heat treated and rapidly quenched to a superelastic condition.

Abstract: An apparatus for pointing twist drill bits includes a processing unit which has a rotary index plate on which are mounted a plurality, e.g., five, of drill bit holders which are circumferentially spaced apart at equal, e.g., 72-degree intervals, and a loading unit which has located adjacent to the index plate a rotary pedestal on which are mounted an equal number of transfer arms. Located around the periphery of the processing unit and loading unit are a plurality of processing stations and loading unit operation stations, respectively.

Abstract: The invention includes methods of manufacturing shafts to be used in medical devices. In particular, methods are disclosed to improve straightness and profile of wire used to form guidewires. The wire is preferably twist-straightened with a desired twist orientation, followed by grinding a desired profile on an apparatus having a spin configuration that is aligned in the same direction as the twist orientation.

Abstract: A grinding wheel (28) that rotates around an axis and that has a working area consisting of an annular surface with a circular arc profile in axial cross section is used to first generate a surface on a cutting blade (22) by grinding with the annular surface during a first orientation in space between the grinding wheel (28) and the cutting blade (22) by means of at least one first relative translational movement between the same, and subsequently at least one part of the generated surface is reground with the annular surface during a second orientation in space between the grinding wheel (28) and the cutting blade (22) by means of at least one second relative translational movement between the same. The grinding wheel (28) is a diamond cup-type grinding wheel. One part (34′) of the working area (34) is located in a face area and another part (34″) is located in a cylinder area of the grinding wheel (28).

Abstract: A grinding wheel and a method for grinding bar blade for the production of spiral gear teeth are described. For economical grinding of such bar blades the grinding wheel has a conical grinding surface (Pp) widening from a small diameter (d1) to a large diameter (d2), a cylindrical grinding surface (Ps) adjoining the conical grinding surface (Pp), and a toroidal grinding surface (G) adjoining the cylindrical grinding surface (Ps). The grinding wheel embodied in this manner enables profile grinding (rough grinding) and subsequent generating grinding (finish grinding) of the surfaces of the bar blade without the necessity of remounting the blade. For practical purposes the grinding wheel rotates about a stationary axis (S), and the bar blade to be ground is guided along the grinding wheel at appropriately set angles.

Abstract: A method of making a drill comprising a tip (16), a shank (10) and a flute area having chip spaces (12, 14) formed therein, the drill being substantially completely coated with a hard material, and is characterized by applying an abrasive material to merely the tip (16) before coating the drill with the hard material. The drill may more particularly be a solid carbide drill.

Abstract: The present invention provides a method of machining a female screw groove in a workpiece whereby the spindle of an internal grinding wheel for machining the workpiece into a female screw is tilted relative to the screw's axis at an angle (&xgr;) smaller than the lead angle (&agr;) of the female screw. First, specifications of the female screw, data on the configuration of the thread groove, and the tilt angle are supplied to a program for calculating data on dressing of the grinding wheel wherein the locus of the groove on cross-sections normal to the axis of the grinding wheel and wheel dressing data are calculated. Second, the grinding wheel on the aforementioned spindle is shaped or dressed by simultaneous triaxial control of the rotation of the single point dresser about a b-axis, and the feed of the grinding wheel table along a z-axis and a cross slide along an x-axis based on the foregoing data. Thereupon, the female screw is machined with the dressed grinding wheel.

Abstract: A grinding method comprises steps of simultaneously grinding plural grinding portions of a workpiece by plural grinding wheels T1, T2 moved individually each other, and terminating said grinding by a predetermined grinding wheel T1 prior to a termination of said grinding by the other grinding wheel T2. Whereby, a content of the grinding by each grinding wheel T1, T2 can be same. A grinding condition in each grinding by each grinding wheel T1, T2 can be changed in accordance with a measuring result of the grinding portion in the grinding.

Abstract: A drill bit sharpener includes a motor assembly and a drill bit grinding assembly. The motor assembly has a motor with a drive shaft to drive the drill bit grinding assembly, which includes a driven assembly, a sharpener housing, a grinding wheel assembly and a bit guide assembly. The sharpener housing is attached to the motor assembly, and the grinding wheel assembly is rotatably mounted in the sharpener housing and is rotated by the driven assembly. The bit guide assembly is mounted in the sharpener housing above the grinding wheel assembly. An adjusting screw in the bit guide assembly is used to adjust the grinding wheel assembly relative to the bit guide assembly. Multiple bit guide holes correspond to the grinding wheel assembly are defined in the bit guide assembly and allow a drill bit to pass through to abut the grinding wheel.

Abstract: A grinding machine for welding electrodes comprises a housing 1, grinder motor 2, grinding disk 3, swing plate 4, holder guide 6, electrode holder 7, electrode turning motor 8 and swing plate moving mechanism 9. The axis &phgr;a of electrode A extends along a line perpendicular to the axis &phgr; of motor drive shaft 2a and first grinding part 3a of the grinding disk is formed to conform to the finishing contour of electrode A. The grinding disk is turned by the grinder motor and at the same time electrode A is turned by the electrode turning motor. The grinding machine, using one grinding disk, grinds the end portion of an electrode to final form and finishes the tip end of the electrode to a mirror surface.

Abstract: Flute grinding cemented carbide workpieces with a diamond containing resin bond grinding wheel is improved by restricting the diamond to comprise a silver-coated diamond; conducting the grinding in the presence of a lubricant consisting of only straight oil; and conducting the grinding at a wheel speed of less than about 30 m/s and preferably about 20 m/s. The preferred diamond is coated with about 25% and 75% silver by weight.

Abstract: An ultra-hard semiconductive polycrystalline diamond (PCD) material formed with semiconductive diamond particles doped with Li, Be or Al and/or insulative diamond particles having semiconductive surfaces, tools incorporating the same, and methods for forming the same, are provided. The ultra-hard PCD material may be formed using a layer of insulative diamond grit feedstock that includes additives therein, then sintering to convert a plurality of the diamond crystals to include a semiconductive surface. In another embodiment, the ultra-hard PCD material is formed by sintering semiconductive diamond grit feedstock consisting of diamond crystals doped with Li, Al or Be. The ultra-hard semiconductive PCD cutting layer exhibits increased cuttability, especially in EDM and EDG cutting operations.

Abstract: Method for manufacturing endodontic instruments having either helical or non-helical flutes. A method is provided for forming superelastic endodontic instruments having helical flutes, wherein a wire of superelastic material is formed into an instrument blank, and before twisting, the superelastic alloy is brought to an annealed state comprising a phase structure including a rhombohedral phase alone or in combination with austenite and/or martensite, or a combination of martensite and austenite. In this annealed state, the instrument blank is twisted at low temperature, for example less than about 100° C., and advantageously at ambient temperature to the final desired twisted configuration. The twisted instrument is then heat treated and rapidly quenched to a superelastic condition.

Abstract: A CNC tool grinding machine has at least one rotatable grinding wheel (1) movable relative to a workpiece (2) for grinding a flute surface (3) of a blade in the workpiece (2). The machine is programmed with a path for the grinding wheel (1) calculated to grind a smooth cutting edge (5) for the blade, and programmed with perturbations to the path which vary the movement of the grinding wheel (1) to grind a wavy cutting edge (6) in the workpiece. With such a machine, it is possible to grind all surfaces of a wavy cutting edge in a single set up rather than requiring two more grinding and milling operations to form the wavy cutting edge.

Abstract: A machining apparatus (10) comprises a material removing tool (12) movably mounted for removing material from a workpiece (14); means for illuminating (42, 54) a sample area upon a tool surface (34) with excitation radiation; means for receiving (42, 54) sample light emitted from the sample area; a spectral analyzer (54) for performing a spectral analysis of the sample light received; and means for determining (60) the condition of the tool at the sample area from the spectral analysis of the sample light. The wear of the tool (12) is determined as such a condition. Operation parameters of the machining apparatus (10) are adjusted according to the determined wear. An example application is a wafer dicing tool.

Abstract: A method of grinding cutting blades with a grinding wheel having first and second grinding edges. The method comprises rough grinding at least one surface of the cutting blade with the first grinding edge and finish grinding at least one surface of the cutting blade with the second grinding edge.

Abstract: A method and apparatus for deburring nonmetallic machined workpieces. A deburring material of sufficient hardness to debur nonmetallic workpieces without causing scarring thereto is rubbed against a workpiece to effect deburring. The deburring material has a durometer hardness and consequently a coefficient of friction whereby frictional engagement of a burr with the deburring material is stronger than the attachment of the burr to the workpiece and therefore the burr is removed as the deburring material is actuated and brought into contact with the burr. The deburring material can be, e.g., polyisoprene and may be mechanically actuated or actuated by hand.

Abstract: A drill having a cutting edge that is less prone to chipping or fracturing when used in drilling operations, and that can be sharpened or resharpened uniformly and consistently from drill to drill by machine grinding. The drill comprises a body and at least one flute formed in the body that terminates in a cutting edge at the cutting end of the drill. The flute has a cutting surface, the cutting surface having formed therein a dub face having a substantially planar surface over at least a portion thereof that is proximate to the cutting edge. The cutting edge has formed therein a cutting land having a substantially planar surface over at least a portion thereof connected at an edge to the planar surface portion of the dub face.

Abstract: A method and jointing attachment 10 for jointing the inserted tooth carbide heads 105 on the top 102 and bottom 103 rotary cutter heads of a thickness planer 100 having a movable carriage 104 that supports the bottom cutter head 103 and is provided with a laterally translatable grinding element 108 wherein the jointing attachment 10 includes an auxiliary motor member 40 that is mounted in a pivoted free floating fashion relative to the movable carriage 104 of the thickness planer 100 and supported by a drive belt member 50 that is attached to a selected one of the rotary cutter heads 102 103 and a pulley reel 43 mounted on the output shaft 42 of the auxiliary motor member 40 for imparting a counterclockwise rotation of the selected cutter head 102 103 to joint the inserted tooth carbide heads 105 through engagement with the grinding element 108.

Abstract: A completely automated apparatus for verifying the identity and geometry of drill bits, re-sharpening the cutting tip of a drill bit and re-positioning a locating ring upon the shank portion of the drill bit subsequent to the re-sharpening of the cutting tip thereof. The apparatus comprises a housing having a pair of cassette trays, a pair of grinding assemblies, a pair of optical assemblies, a pair of primary cleaning assemblies, a pair of secondary cleaning assemblies, a pair of inversion assemblies, a pair of workhead assemblies, a bumping assembly, and a loader assembly attached thereto. The workhead and loader assemblies are used to transport drill bits between the cassette trays and other assemblies in a selected sequence which is controlled and coordinated by a programmable control device. The control device is electrically interfaced to each of the assemblies and allows the cutting tip re-sharpening and locating ring re-positioning processes to be conducted simultaneously on at least two drill bits.

Abstract: A magnetic head cluster is provided along with a method of making a magnetic head cluster. The magnetic head cluster comprises a substrate having a plurality of magnetoresistive (MR) read and inductive magnetic write transducers and a plurality of terminals formed thereon. A plurality of lapping guides are also provided on the substrate between adjacent transducers.

Abstract: A completely automated apparatus for verifying the identity and geometry of drill bits, re-sharpening the cutting tip of a drill bit and re-positioning a locating ring upon the shank portion of the drill bit subsequent to the re-sharpening of the cutting tip thereof. The apparatus comprises a housing having a pair of cassette trays, a pair of grinding assemblies, a pair of optical assemblies, a pair of primary cleaning assemblies, a pair of secondary cleaning assemblies, a pair of inversion assemblies, a pair of workhead assemblies, a bumping assembly, and a loader assembly attached thereto. The workhead and loader assemblies are used to transport drill bits between the cassette trays and other assemblies in a selected sequence which is controlled and coordinated by a programmable control device. The control device is electrically interfaced to each of the assemblies and allows the cutting tip re-sharpening and locating ring re-positioning processes to be conducted simultaneously on at least two drill bits.

Abstract: Flute grinding cemented carbide workpieces with a diamond containing resin bond grinding wheel is improved by restricting the diamond to comprise a silver-coated diamond; conducting the grinding in the presence of a lubricant consisting of only straight oil; and conducting the grinding at a wheel speed of less than about 30 m/s and preferably about 20 m/s. The preferred diamond is coated with about 25% and 75% silver by weight.

Abstract: An end mill grinder have two independently adjustable grinding wheels. The end mill grinder includes two grinding wheels which are located next to each other. Each grinding wheel is rotated by a motor. The grinding wheels are positioned in a manner which allows the first grinding wheel to grind primary clearances of the end mill, while the second grinding wheel grinds secondary clearances of the end mill. The end mill is guided toward the grinding wheels by a finger guide attached to a carriage which supports and retains the end mill. The end mill grinder allows the grinding of primary and secondary clearances in one step.

Abstract: The invention described herein discloses a chemical mechanical machining and surface finishing process. A conversion coating is formed on the surface of a workpiece and is removed via relative motion with a tool, thereby exposing the workpiece to further reaction with the active chemistry. Low mechanical forces are used such that the plastic deformation, shear strength, tensile strength and/or thermal degradation temperature of the workpiece are not exceeded. Since the chemical mechanical machining and surface finishing process requires little force and/or speed of contact to remove the conversion coating, the equipment's mass, complexity and cost can be significantly reduced, while simultaneously increasing machining precision and accuracy. The present invention lends itself to a very controlled rate of metal removal, and can simply surface finish the workpiece, or if desired, can surface finish the workpiece simultaneously with the shaping and/or sizing process.

Abstract: This invention results from the realization that a drill bit can be positioned for sharpening without using the flawed tip as a reference point allowing the drill bit to be sharpened with an insignificant level of human judgment and with consistently less flawed results. This inventive method for properly positioning a drill bit to be sharpened involves selecting a drill bit with a substantially helical geometric shape, a feature common to most drill bits. The next step is viewing a drill bit with a digital imaging device. Either an individual or, preferably, a computer determines the geometric shape of the drill bit. An individual or automated mechanism then calculates a sharpening position, relative to a sharpening means, such as sharpening wheels, for sharpening the drill bit based on the geometric shape of the drill bit. Automating this step may involve calibrating the machine by first manually positioning the drill bit and then programming a machine to similarly position all similarly shaped drill bits.

Abstract: A grinding wheel for producing a cutting tool having a flute and a land along with double margins which follow a helix angle is disclosed along with a method for using such a grinding wheel. Additionally, a crush roll for dressing such a grinding wheel is disclosed.

Abstract: A grinding apparatus for grinding a spline ball groove on a workpiece comprises a rod-shaped grindstone, having a distal end portion with a curved surface corresponding to the groove to be ground, and a spindle mechanism for rotating the grindstone. The spindle mechanism and the grindstone are supported by means of a supporter in a manner such that they are inclined at a given angle to an axis of the workpiece. A rotary dresser, which has a dress groove corresponding to the curved surface of the distal end portion of the grindstone, is disposed near the grinding apparatus. The grindstone can be reciprocated along the axis of the workpiece by a drive mechanism between the workpiece and the dresser without changing its angle of inclination.

Abstract: This invention results from the realization that a drill bit can be positioned for sharpening without using the flawed tip as a reference point allowing the drill bit to be sharpened with an insignificant level of human judgment and with consistently less flawed results. This inventive method for properly positioning a drill bit to be sharpened involves selecting a drill bit with a substantially helical geometric shape, a feature common to most drill bits. The next step is viewing a drill bit with a digital imaging device. Either an individual or, preferably, a computer determines the geometric shape of the drill bit. An individual or automated mechanism then calculates a sharpening position, relative to a sharpening means, such as sharpening wheels, for sharpening the drill bit based on the geometric shape of the drill bit. Automating this step may involve calibrating the machine by first manually positioning the drill bit and then programming a machine to similarly position all similarly shaped drill bits.

Abstract: A sharpening guide assembly for use in sharpening ski and snowboard edges includes an angle member and at least one riser member. The angle member includes at least a first outer surface and a second outer surface, an inner edge of the first outer surface adjoining an upper edge of the second outer surface. The riser member is positioned on the first outer surface of the angle member such that a top portion of the riser member extends above the first surface of the angle member. The angle member is formed of a first material and the riser member is formed of a second material, wherein the second material has a hardness which is greater than a hardness of the first material. During a sharpening operation, a sharpening tool is supported on the riser member such that the sharpening tool such as a file member is positioned above the first outer surface of the angle member so as to avoid potential wear causing contact therewith.

Abstract: Described is a method for the cutting machining of non-circular contours using a tool in the shape of a cone or a truncated cone positioned on a spindle for rotation, said spindle aligned at a certain angle with the workpiece axis on which the workpiece with the contour is positioned, whereby the tool is swiveled during the machining about at least one first swivel axis that is different from the spindle axis. Alternatively, the workpiece can be moved correspondingly, and the tool may remain unchanged in its alignment. Tool and workpiece also may undergo a corresponding movement together, since the crucial factor is solely the relative movement between tool and workpiece. Also described is a device for performing the method.

Abstract: It is an object of the invention to provide a thread-forming tap to which a chamfer can easily be mounted, and a general threading method. The thread forming tap of the invention has a threaded portion comprising a tapered chamfer and a parallel threaded portion which is formed continuously with the chamfer. A depth of root of the chamfer is set equal to that of a root of the parallel threaded portion constantly.

Abstract: A fixture for selectively locating and retaining hydraulic gerotor rotors in position in respect to a grinding wheel, the fixture clamping the rotor between two oversized positioning rolls located in rotor lobe valleys on opposite sides of the rotor.

Abstract: An apparatus and method for honing, sharpening or grinding a curved peripheral cutting surface of a slicer blade are provided. Included is the use of one of a set of interchangeable cams that generally follows the curved shape of the blade cutting surface, whether same has a constant radius or varying radii. The honing is accomplished off-line of the slicer equipment, and the movement of two honing or grinding wheels is closely controlled so as to provide honed or ground cutting edges which are of substantially uniform width throughout their respective peripheries. The two honing or grinding wheels operate independently of each other on opposing edges of the blade, a large blade load area is provided therebetween, precision gib adjustments are provided between the wheel and the cam follower, and a single tool is needed to make adjustments of the apparatus.

Abstract: A cup-shaped grindstone for grinding an end face of an annular portion of a work to form tooth grooves in the end face includes a grinding portion provided around an outer periphery of a disk portion. Abrasive grains of CBN are electrodeposited on each of first, second and third grinding faces of the grinding portion. Cooling-liquid ejecting bores are provided in a lower end of the first grinding face. To form the tooth grooves, the following steps are carried out: a rough-finish processing step cuts the tooth grooves by intermittently feeding the cup-shaped grindstone in a predetermined amount at a time, and a finish processing step of finishing the tooth grooves by retaining the cup-shaped grindstone at a predetermined position after the rough-finish processing step. During both steps, a cooling liquid is supplied from cooling-liquid ejecting bores defined in the first grinding faces of the cup-shaped grindstone.

Abstract: For producing hectically profiled workpieces (1) the helical profile (2) is first of all prefabricated by a milling treatment and is then finished by a grinding treatment of the profile surface. To achieve optimum machining qualities in an economic way, the grinding treatment is performed with a grinding tool (6, 12) adapted to the milling tool (3, 9) for the milling treatment in terms of shape, size, position of the axis of rotation and cutter arrangement.

Abstract: A completely automated apparatus for verifying the identity and geometry of drill bits, re-sharpening the cutting tip of a drill bit and re-positioning a locating ring upon the shank portion of the drill bit subsequent to the re-sharpening of the cutting tip thereof. The apparatus comprises a housing having a pair of cassette trays, a pair of grinding assemblies, a pair of optical assemblies, a pair of primary cleaning assemblies, a pair of secondary cleaning assemblies, a pair of inversion assemblies, a pair of workhead assemblies, a bumping assembly, and a loader assembly attached thereto. The workhead and loader assemblies are used to transport drill bits between the cassette trays and other assemblies in a selected sequence which is controlled and coordinated by a programmable control device. The control device is electrically interfaced to each of the assemblies and allows the cutting tip re-sharpening and locating ring re-positioning processes to be conducted simultaneously on at least two drill bits.

Abstract: A grinding control unit installed in a tool bit grinder and adapted to control the feeding of a bit relative to a grinding wheel of a grinding unit of the tool bit grinder, the grinding control unit including a U-shaped support, a chuck adapted to hold the bit to be ground, a feeder adapted to control feeding stroke of the bit a swinging control mechanism adapted to control swinging stroke of the bit when feeding the bit, enabling two lips of the tip of the bit to be ground, a horizontal displacement control mechanism adapted to control the depth of bit feeding stroke, enabling the spur of the bit to be well ground.

Abstract: A sharpener assembly for a food slicer includes a rotatable frame with a sharpening member and a truing member operatively connected for rotation with the frame. The frame is mounted on a food slicer to place the sharpening member and truing member on opposed sides of a slicer knife. The frame is rotated to rotate the sharpening member and the truing member into contact with respective sides of the slicer knife.

Abstract: Cylindrical surface regions (1) of cutting tools (2, 21), such as drills, boring tools, reamers or the like, that is, cutting tools formed with chip removal grooves or flutes or recesses (6), are ground by engaging a rotary cutting disk (3) against the ribs (5) between the chip removal grooves. The cutting tool (2, 21), during the grinding operation, is rocked or oscillated to-and-fro (24) about its longitudinal axis (18) in such a manner that the cutting disk (3) covers the cylindrical surface portion in circumferential direction at least several times. The cutting disk (3) also may rock or oscillate about an axis perpendicular to the axis (7) of rotation of the cutting disk (3). Suitable frequencies are between about 0.1 Hz and 1 Hz, preferably 0.5 Hz, for the rocking movement of the cutting tool (2, 21), with the oscillatory movement of the grinding disk being higher than that of the cutting tool, and for example between 1 Hz and 10 Hz.

Abstract: An apparatus and method for sharpening a disc blade includes a grinding wheel mounted on a housing. The housing is mounted on a drive shaft so that the housing rotates with the drive shaft but can move axially relative to the drive shaft. A transversely extending projection on the housing extends into a space between two axially spaced spacers on the drive shaft. A spring is positioned between each spacer and the projection for resiliently biasing the housing in an axial direction.

Abstract: A sharpening device for the cutting knife (12) of a face-to-face weaving machine, comprising a belt-shaped sharpening means (4) of a flexible material provided with a sharpening face that is so disposable that the cutting knife (12) during its back and forth going movements comes into contact with this sharpening face, and that is movable in order to bring various areas of the sharpening face within reach of the cutting knife (12). The sharpening means (4) can be unwound from a reel (7) and be wound up by another reel (3) in order to bring several areas of the sharpening face within reach of the cutting knife (12). The two reels (3), (7) and the belt-shaped sharpening means (4) can be made as a detachable unit. The sharpening means (4) preferably runs with the sharpening part over an elastically disposed curved surface (9).

Abstract: A universal grinding machine having a plurality of workpiece holders, each of which can be moved independently of each other or jointly, by a separate slide, in the longitudinal direction of the workpiece on a slide guide disposed on the machine bed, or which can be fixed independently of each other or jointly to the machine bed.

Abstract: Significantly improved resistance to breaking while drilling in metal can be realized in twist drill bits having a web thickness taper which is about twice the web thickness taper specified in Standards and in common use in the industry. This creates much shallower flutes and flies in the face of conventional wisdom in the art which holds that the web taper rate should be low to maximize the amount of flute volume available to convey chips and sawdust out of the hole. A flute length of about 1/2″ less than the flute lengths specified by the Standards makes it possible to have such a large taper rate but still control variations in tolerances for the flute length. It also provides a marking zone for placing size indicia on the drill bit shank outside the portion which is gripped by the chuck jaws of a power drill.

Abstract: The invention is a grinding apparatus for grinding tips of welding electrodes.

Abstract: A superelastic endodontic instrument, such as a file, is formed by grinding a superelastic wire to form a file preform or blank, and rotating a first end of the blank while preventing rotation of a second end of the blank. The file blank is maintained in the austenite phase at least until twisted to form a stress induced martensite which is plastically deformed by the twisting. A heat treatment step may be performed prior to twisting, during twisting or after twisting of the preform. The file blank may be heated by electrical heating methods or by submerging the blank in a heated liquid.

Abstract: An improved process for producing an endodontic instrument with a predetermined taper having a plurality of flutes, each with a predetermined number of spirals over a predetermined length of the instrument are provided. The process basically comprises providing a grinding wheel rotated about a first axis having a plurality of flute grinding ribs and a rolled deformed metal grinding rib extending from a periphery thereof. A rotating wire stock is fed past the plurality of flute grinding ribs and the rolled deformed metal grinding rib at a controlled rate along a second axis so that a separate flute is ground on the wire stock by each of the flute grinding ribs and rolled deformed metal is removed from the ground wire stock by the rolled deformed metal grinding rib.

Abstract: An object of the present invention is to provide an apparatus which is suitable for sharpening the drill bits of both the power drill and hand drill. Additionally, the operation of said apparatus is simple, and the sharpening is accurate.

Abstract: An adapter for use with a powered grinding tool having a driven grinding wheel has a pivotally mounting part on a body thereof, and a drill bit holder engageable with the mounting part in either of two orientations for sharpening a tip of a drill bit clamped in a set position in the drill bit holder at the grinding wheel, the engagement being completed when the drill bit engages on a stop bar at the front of the mounting part. Also disclosed is a setting arrangement for setting the drill bit in its holder including stop means for engagement by the drill tip upon longitudinal setting of the drill bit, and drill rotation setting means slidable relative to the stop means for rotational setting of the drill bit. A powered grinding tool having the features of the adapter formed as part thereof is also disclosed.