Abstract: Methods for manufacturing an endodontic instrument or device, such as an endodontic file for use in performing root canal therapy on a tooth, are disclosed. The method may include the steps of: (a) providing a wire or wire blank comprising a nickel titanium alloy that has been heat-treated at a heat-treat temperature and has an angle greater than 5 degrees of permanent deformation after torque at 45 degrees of flexion tested in accordance with ISO Standard 3630 Part 1: General requirements and test methods and (b) removing material from the wire or wire blank to form an endodontic instrument or device. The method may include the steps of: (a) providing a wire or wire blank comprising a nickel titanium alloy at a first temperature; and (b) removing material from the wire or wire blank at a second temperature above the first temperature to form an endodontic instrument or device.

Abstract: A thread whirling device 1 and a whirling ring 3, corresponding thereto, are presented, in which the whirling ring 3 can be attached in a hollow spindle 11 of the thread whirling device 1 in a simple and reliable manner using a combined bayonet-type and clamping connection.

Abstract: A method of orbital milling is performed using an orbital end mill, which has a cutting bit designed for orbital end milling. The abstract of the disclosure is submitted herewith as required by 37 C.F.R. §1.72(b). As stated in 37 C.F.R. §1.72(b): A brief abstract of the technical disclosure in the specification must commence on a separate sheet, preferably following the claims, under the heading “Abstract of the Disclosure.” The purpose of the abstract is to enable the Patent and Trademark Office and the public generally to determine quickly from a cursory inspection the nature and gist of the technical disclosure. The abstract shall not be used for interpreting the scope of the claims. Therefore, any statements made relating to the abstract are not intended to limit the claims in any manner and should not be interpreted as limiting the claims in any manner.

Abstract: A method and apparatus are provided to machine a curved surface such as an inner or outer peripheral surface of a pipe. The pipe is held stationary during machining and a rotatable spindle of a machine head moves along multiple orthogonal axes to align the rotational axis of the spindle with the longitudinal pipe axis. Preferably, the pipe axis is located by using a touch probe to engage the curved surface at multiple spots and the calculating the location of the pipe axis. The cutting tool, which is preferably a cutting tool insert, is rotated by the spindle to machine the curved surface.

Abstract: As shown in a development view of FIG. 2, spiral flutes 16a and 16c have a lead angle ? different from a lead angle ? of spiral flutes 16b and 16d adjacently placed circumferentially to allow the lead angle ? of cutting edges 20a and 20c, formed along the spiral flutes 16a and 16c, respectively, to be different from the lead angle ? of cutting edges 20b and 20d adjacently placed circumferentially. This causes the cutting edges 20a to 20d to have intervals that axially vary in series such that the cutting edges 20a to 20d have unequal intervals. This results in irregular increase or decrease in milling resistance encountered during milling of a thread, thereby suppressing the occurrence of chatter vibration due to resonance with a capability of milling the thread with excellent milling precision under various milling conditions.

Abstract: The invention relates to a drill thread milling cutter (1) for producing a bore and for the subsequent milling of a thread in the bore, said drill thread milling cutter (1) having a working region (2), on the circumference (3) of which a number of drilling and milling cutting edges are arranged. A number of milling cutting edges (7, 8, 9, 10) greater than the number of drilling cutting edges (17) by a factor greater than 2 are arranged or are effective in the direction of rotation.

Abstract: The frame of the whirling head comprises the rigid casing (7), in which the part (10) contains the drive pulley (15) solidly attached to the coupling member (17) connected to the drive shaft of the spindle (26). By means of the belt (19), this pulley (15) drives the pulley (8) solidly attached to the connecting cone (4), which in turn comprises the internal milling cutter (1) which cuts the thread of the screw shaft (27) supported between the bar advance unit (28) and the tailstock centre (29). The latter is mounted as an exchangeable tool on the return unit (32).

Abstract: A thread mill that is to be moved along a helical interpolation path while being rotated about an axis of the thread mill in a rotating direction, for forming a thread in a circumferential surface of a workpiece. The thread mill includes a cylindrical main body having (a) at least one spiral flute formed in an outer circumferential surface of the cylindrical main body, and (b) at least one cutting edge each provided by a rear-side one of widthwise opposite edges, as viewed in the rotating direction, of a corresponding one of the at least one spiral flute. Each of the at least one spiral flute extends in a direction opposite to the rotating direction as viewed in a direction away from a proximal end of the cylindrical main body toward a distal end of the cylindrical main body. Also disclosed is a method of forming the thread by using the thread mill.

Abstract: A numerical control unit issues a sequence of instructions for causing a spindle of a cutter disk in a tool machine to perform successive straight displacements approximating a spiral of Archimedes, with a predetermined angle step from one point to the next, and issues one or more ADIS instructions for merging each of the straight displacements with the next. The spiral path is such that the cutter disk will progressively shave a chip of a predetermined thickness over several revolutions, until its cutting edge is near the intended groove bottom. The tool is then caused to follow a merging path leading to a final point lying on the intended groove bottom, and finally is caused to follow a full circular path coaxial to the bore starting from the final point.

Abstract: An orbital machining apparatus for producing a workpiece hole with a cutting tool, including: a first actuator for rotating the tool about its longitudinal center axis during the machining of the hole; a second actuator for moving the tool in an axial feed direction substantially parallel to the tool axis; a third actuator for rotating the cutting tool about a principal axis; and a radial offset mechanism. The third actuator includes a rotating drive driven by a motor, a carrier ring connected to and rotated by the drive by two opposed, radial drive pins. The ring performs a radial sliding movement relative to the drive while being rotated thereby. Two opposed, radial carrier guide shafts circumferentially spaced 90° from the drive pins and connecting the ring and an inner cylindrical eccentric body such that the latter may perform a radial sliding movement relative to the ring while being rotated thereby.

Abstract: A thread forming tool includes an elongated body defining a longitudinal center axis. The body including a thread forming portion formed by one or more annular ridges oriented perpendicular to the axis. The body has a non-circular shape in a cross sectional plane oriented perpendicular to the axis at an axial center of the ridge.

Abstract: A thread cutting milling tool comprises a shank with a working portion formed with a recess for receiving a thread cutting insert. The thread cutting insert has one edge formed with a line of thread-form teeth of identical profile. The thread cutting teeth project laterally for cutting engagement with a work-piece while the tool spins about its axis. The tool also orbits within or about a work piece, and in one orbit of the tool in a helical cutting path relative to the work piece a number of complete turns of the screw-thread are formed which is equal to the number of teeth of the insert in engagement with the work-piece. A secondary cutter carried on the thread cutting milling tool provides for formation of a pilot portion or counter bore on the work piece at an end of the screw thread. The pilot portion or counter bore provides for alignment of a threaded member which is to engage the screw thread.

Abstract: The present invention relates to a thread milling cutter, which includes a cutting head, having a holder with a number of cutting insert pockets, a number of threading inserts, which are received in the cutting insert pockets and an attachment integrated with the cutting head, which attachment is intended to be received in a tool coupling. The invention also relates to the holder per se and to a method for milling an external thread on a spigot. The holder is provided with an internal cavity, which has an extension both radially and axially with regard to a rotational axis of the thread milling cutter, and the cutting insert pockets are provided in the internal cavity.

Abstract: A thread cutting milling tool comprises a shank with a working portion formed with a recess for receiving a thread cutting insert. The thread cutting insert has one edge formed with a line of thread-form teeth of identical profile. The thread cutting teeth project laterally for cutting engagement with a work-piece while the tool spins about its axis. The tool also orbits within or about a work piece, and in one orbit of the tool in a helical cutting path relative to the work piece a number of complete turns of the screw-thread are formed which is equal to the number of teeth of the insert in engagement with the work-piece. A secondary cutter carried on the thread cutting milling tool provides for formation of a pilot portion or counter bore on the work piece at an end of the screw thread. The pilot portion or counter bore provides for alignment of a threaded member which is to engage the screw thread.

Abstract: A milling head for thread whirling, the milling head includes a plurality of cutting elements evenly disposed around a center hole, each cutting element in the plurality of cutting elements includes at least two cutting surfaces formed thereon. Any one of the at least two cutting surfaces is selectable to extend within the center hole for contacting a work-piece. Each cutting element in the plurality of cutting elements is disposed in a recess formed in a face of the milling head, with each recess defining at least two walls. Each of the at least two walls contacts a side of the cutting element to align the cutting element in a predetermined relationship with respect to the milling head. In one embodiment, the plurality of cutting elements include first and second sets of cutting elements. The first set of cutting elements is evenly disposed around the center hole and contact the work-piece to produce a thread form on the work-piece.

Abstract: A machining apparatus for machining a workpiece by rotating and revolving either the workpiece or a tool 1 to contact with each other. The machining apparatus comprises rotation/revolution ratio setting motors M1 and M3 for setting a ratio of a number of rotations to a number of revolutions of the workpiece or the tool 1, to a numerical value having a fraction below a decimal point, by changing the number of revolutions. The workpiece is machined by setting the number of revolutions and the number of rotations at the ratio.

Abstract: A method and cutting tool for producing a hole or a recess in a workpiece which includes flat or curved sheets of fiber-reinforced composite material, metal or combinations thereof. The cutting tool has a shaft with a longitudinal axis and an axial cutting surface and at least one cutting edge disposed on the axial cutting surface and extending radially from the longitudinal axis with a gap between the radial inner extent of the cutting edge and the longitudinal axis. The method of use includes rotating the cutting tool about its longitudinal axis and also translating the cutting tool during rotation.

Abstract: A milling head for thread whirling, the milling head includes a plurality of cutting elements evenly disposed around a center hole, each cutting element in the plurality of cutting elements includes at least two cutting surfaces formed thereon. Any one of the at least two cutting surfaces is selectable to extend within the center hole for contacting a work-piece. Each cutting element in the plurality of cutting elements is disposed in a recess formed in a face of the milling head, with each recess defining at least two walls. Each of the at least two walls contacts a side of the cutting element to align the cutting element in a predetermined relationship with respect to the milling head. In one embodiment, the plurality of cutting elements include first and second sets of cutting elements. The first set of cutting elements is evenly disposed around the center hole and contact the work-piece to produce a thread form on the work-piece.

Abstract: A hand tool apparatus uses a cutting tool with a first width and a tool axis to machine a hole in an object. The hole has a second width at least as large as the first width of the cutting tool. The apparatus includes a housing, a spindle unit in the housing for rotating the cutting tool and an orbital drive for rotating the spindle unit. An axial feed mechanism moves the orbital drive and the spindle unit jointly either toward or away from the object being machined.

Abstract: An orbital machining apparatus for producing a hole in a workpiece using a cutting tool and including a first actuator for rotating the cutting tool about its longitudinal center axis, a second actuator for moving the cutting tool in an axial feed direction, a third actuator for rotating the cutting tool about a principal axis and a radial offset mechanism. The radial offset mechanism includes an inner cylindrical body having an eccentric cylindrical hole and which supports a spindle unit, the inner cylindrical body radially supported in an eccentric cylindrical hole of an outer cylindrical body to adjust the radial distance of the cutting tool longitudinal center axis from the principal axis. The third actuator includes first and second motors which rotate the outer and inner cylindrical bodies, respectively, in synchronism to maintain a mutual rotary position thereof to keep a cutting tool radial offset position unchanged during operation.

Abstract: A cutting tip having a three-layer laminated structure is provided. The tip is made from a disc-shaped three-layer laminate wherein a second layer consisting of a hard sintered compact of CBN or diamond is sandwiched by a first layer and a third layer consisting of a tool material such as cemented carbide. Prismatic blanks of rectangular cross-section are cut out by cutting the three-layer laminate in strips. Semi-completed tips of a desired shape are obtained by cutting up the prismatic blanks. Desired cutting edges are formed on the semi-completed tips to produce completed tips. Because prismatic blanks are obtained from a three-layer laminate and semi-completed tips are cut out from the prismatic blanks like this, the semi-completed tips can be obtained in large numbers, yield is high, and the manufacturing cost of the tip can be reduced.

Abstract: A pipe end thread cutting apparatus includes three milling cutter heads mounted on a support wall which is vertically movable with the heads mounted symmetrically about a central axis in use; a gripping chuck for holding a pipe end is mounted on a rotatable shaft carried on a support member which is movable toward and away from the milling cutter heads and motor drives are provided for each cutter head.

Abstract: A thread milling tool includes a proximal shank portion and a distal cutting portion. The cutting portion includes at least one thread milling tooth and at least one flute oriented helically, or spirally, about a rotational axis of the tool. The helix angle of the thread milling tool of at least 20°. The cutting portion may be configured to form internal or external threads in a workpiece as the cutting portion moves relative to the workpiece.

Abstract: The invention involves a threading tool (20) for defining an internal thread within walls (62) of a cavity (64) within a workpiece having a floor (66) around an axially disposed protuberance (68) with a top (70) extending from the floor (66). The threading tool (20) includes a first end portion (22) for gripping and a second end portion (24) for threading. Threads (30) are formed on the second end portion (24). An opening (40) is axially disposed at the second end portion (24) and extends inward to form a recess (42) and recess bottom (44) over which the threads (30) extend a distance (A), allowing internal threads to be formed along the walls (62) past the top (70) of the protuberance (68).

Abstract: A milling tool for thread-milling and boring has a milling region with thread-milling cutters disposed on thread-milling teeth, and bore-milling cutters disposed on an end face. The tool regions where the milling cutters are disposed are made of hard materials. The thread-milling cutters have a rake angle. The tool is successfully used to mill high-strength materials. The rake angle of the thread-milling cutters is zero or negative, and a coating of hard material is present in the region of the milling cutters. The combination of features including the use of hard material in the cutting region of the tool, the provision of a coating of hard material in the cutting region, and a zero or negative rake angle, enables use of the milling tool for thread-milling and boring with high-strength workpieces without problems and without experiencing high wear.

Abstract: A complex cutting-blade tool wherein a neck having a smaller diameter than the diameter of the drill thereof is connected to a shank. At the place where the drill and the neck are connected is provided a burr removal cutting blade inclined roughly 45° from the tool center axis. A hole entrance beveling cutting blade is also mounted through fixture to the neck, inclined at an angle of roughly 45° from the tool turning center axis, in a direction opposite to the burr removal cutting blade. The fixture can be secured at any position along the length of the neck, wherefore the distance between the burr removal cutting blade and the hole entrance cutting blade can be suitably adjusted so as to correspond to the depth of the machined hole (i.e. the thickness of the workpiece).

Abstract: A tool holder for a tool drive with an outer and an inner concentric drive shaft. A first adapter is detachably held by a conventional clamping system in a receptacle of the outside drive shaft. A second adapter is concentrically mounted in the first tool receptacle of the first adapter so as to rotate with respect to the first adapter. The second adapter has a tool receptacle which can be inclined by a pivoting element. Thus, a tool can be eccentrically inserted and concentrically driven. This makes possible certain machining modes, for example the machining of a hollow shaft, since inner threads can now be turned rather than cut.

Abstract: A machine for forming threads in a cylindrical bone dowel made of bone material, comprising a planar surfaced base provided with a threaded guide member having an externally threaded portion. A holding and rotating assembly is mounted on the base to rotatably hold the bone dowel so that the central axis of the bone dowel extends in the axial direction of the threaded guide member, An essentially planar support member is mounted on the guide member for movement with respect to base and an angle adjustment assembly is mounted to the support member. A cutting assembly having a cutting member in the form of a burr is also mounted on the support member so that when the threaded guide member is rotated the cutting assembly and associated cutting member is carried by support member to engage the bone dowel.

Abstract: A drive apparatus for a simultaneous operation machine includes a plurality of pulleys and drive belts in a unique orientation to simultaneously drive a plurality of spindles. A first outer spindle is driven about a first axis of rotation to perform a first operation such as machining. An inner spindle is disposed within the outer spindle and is driven about a second axis which is offset from and parallel to the first axis to simultaneously perform a second operation, such as grinding. Additionally, the drive apparatus is capable of rotating the second spindle about the second axis while orbiting about the first axis, and simultaneously rotating of the first spindle about the first axis. Preferably, a single motor is provided for driving both of the outer and inner spindles.

Abstract: A thread milling cutter including a shank and a milling region adjoining the shank at a front end of the shank and including at least two rows of teeth and extending parallel to each other, with the teeth of both rows having the same height and forming each two flanks, with the respective teeth of both rows being associated with respective circumferential planes, and with one flank of a respective tooth of one of the rows being shifted, viewed in a circumferential direction, in an axial direction, forward with respect to one flank of a respective tooth of another of the rows, or another flank of the respective tooth of the another of the rows being shifted viewed in a circumferential direction, in the axial direction, backward with respect to another flank of the respective tooth of the one of the rows, the one flank forming a front offset and another flank forming a rear offset, with front and rear offsets alternating with each other.

Abstract: Solid tungsten carbide is the popular material for these combinations tools. High resultant side forces on the tool during the thread milling phase are caused by relatively high circumferential engagement of the tool and a very low feed per tooth (chip thickness). A combined hole making, threading and chamfering tool with staggered thread cutting teeth doubles chip thickness and reduces side forces (resulting in less engagement), consequently allowing the feed rate to be increased while reducing thread milling time. In addition, this arrangement also reduces tool chatter, thus providing a smoother surface finish in the thread. In one form, the cutting teeth are formed on one or more removable inserts, facilitating replacement or substitution thereof.

Abstract: A hole cutting tool for holemaking, chamfering, grooving, threading and/or O-ring grooving. The tool is a rotary tool for holemaking in a workpiece which includes one or more holemaking inserts about the outermost end of the tool, at least a pair of axially spaced apart chamfering inserts radially sunken into the intermediate portion of the tool, and one or more grooving inserts also radially sunken into the intermediate portion of the tool between the chamfering inserts, all of which provides for holemaking with chamfered entrance and exit edges and/or a slot, groove, or threads within the hole. An additional O-ring grooving insert may be provided to cut an annular groove around the hole on an end face of the workpiece.

Abstract: A drilling and thread-milling tool for generating an internal thread in a workpiece, including a proximal shank portion attachable to a driving device for rotating the tool about a rotation axis thereof, and a distal cutting portion rotated with the shank portion about the rotation axis for generating the internal thread while the distal cutting portion is moved relative to the workpiece. The cutting portion has at least one thread-milling tooth on an outer circumferential surface thereof, each tooth having a configuration similar to that of the internal thread, and a height substantially equal to a depth of the internal thread. The cutting portion further has at least one end-cutting edge on a distal end face thereof so as to extend in a radial direction thereof, each end-cutting edge having a maximum diameter which is larger and smaller than a minor diameter and a major diameter of the thread-milling tooth.

Abstract: A unitary bore forming and threading tool for producing a variety threaded bores having chamfers and counterbores without a need for tool changes. The improved took preferably includes a shaft of predetermined axial length and having proximal and distal ends, a shank located adjacent the proximal end, a holemaking element located adjacent the distal end, and a threadmill portion located axially between the bit and the shank. The holemaking element further includes a chamfering surface and an end cutting surface. The disclosed tool and method enable creation of a variety of bores such as chamfers, counterbores, and threaded bores by producing bore portions of selectively determined distinct diameters by sequentially axially feeding the tool into the workpiece along distinct tool paths without changing tools. If desired, one or more of the bore portions can be threaded with the threadmill by moving the threadmill in a selectively determined helical or nonhelical path.

Abstract: A threaded hole (20) in a workpiece (22) is formed by rapidly spinning an elongated tool (24) having a drill point (64) at one end, at least one longitudinally extending flute (80) having thread milling faces (84) for milling the thread to be formed, and wherein the tool (24) is first moved axially to carry the drill point (64) against and into the workpiece (22) to form a hole (66), then is displaced radially a distance equal to the thread depth to be formed, then is moved orbitally around the hole (66) to mill threads therein, then is displaced back to the center of the hole (20) and then is retracted from the hole (20). To form a helical thread in the hole (20), the tool (24) is shifted axially one thread pitch during the orbital movement. A thread milling drill head (26) is disclosed for chucking the tool (24) and shifting it through the aforesaid movements.

Abstract: A combination tool is disclosed for drilling a hole in a workpiece on the inward feed of the tool and for threading the hole during retraction of the tool. The tool that has a straight body with a drill point at the forward end, a shank at the rearward end and a thread-form mill between the drill point and the shank.

Abstract: Disclosed herein is a hobbing machine particularly for the production of spur and helical gears. The hobbing machine is characterized in that a separate mechanism for hob shifting is not required. The hob shifting, as well as other machine motions, is carried out by linear movement of the tool and workpiece relative to one another in up to three mutually perpendicular directions. The machine also includes tool support means to which the hobbing tool is mounted and which is rotatably adjustable for controlling the angular orientation of the hobbing tool. A control system including a computer controls the linear movements, angularly adjustable tool support movements, as well as the necessary timed rotations of the tool and workpiece.

Abstract: A description is given of equipment for the production of screw-threaded drilled holes (tapped holes) of variable diameters in solid materials in a single-pass operation with the use of an integrated cutting tool and with the use of a commercially-available hand-drilling machine having an electronically-controlled motor drive, or any other type of drive, where the equipment includes a tool spindle which may be attached to the drive shaft of a hand-drilling machine or the like, and which is radially displaceable in relation to its axis and accommodated in a cylindrical housing for the spindle, where the position of said spindle housing may be adjusted axially in a specified manner by means of a screw device in a holder which may be mounted on the tool and has arrangements, on the one hand, for limitation of the axial travel of the tool and, on the other hand, for adjustment of the desire diameter of the tapped hole which is to be produced.

Abstract: A drilling and thread-milling tool is disclosed which has at its front-end 7 at least one end-cutting edge 8 for making a core-diameter hole and, behind it, non-pitched thread-milling teeth 4 to generate thread pitches and for which are provided an axial motion, rotation about its own axis as well as a helical motion. It is desirable that one tool should be adapted for making core-diameter holes of different diameters essentially by means of the end-cutting edge. This is accomplished in as much as the outer diameter of the end-cutting edge 8 is equal to or smaller than the minor diameter of the thread-milling teeth 4, in that the number of thread-milling teeth 4 arranged in axial succession is less than the number of thread pitches to be produced, in that provision is made for the simultaneous cutting of the core-diameter hole and thread pitches and in that the helical motion serving to generate the thread pitches consists of a number of orbits corresponding to the number of thread pitches to be generated.

Abstract: A spindle driver for a machine tool is disclosed which is adapted to move the spindle and a tool driven thereby in a helical path with variable pitch and with an orbital radius which may be varied. A quill is mounted on a support member and driven by a variable pitch drive mechanism in the form of a differential lead screw to provide a selectable ratio of axial motion to rotative motion of the quill. A spindle carrier is rotatably mounted on the quill for rotation about an eccentric axis offset from the quill axis. A spindle motor and a spindle driven thereby is mounted on a carrier with the spindle axis offset from the eccentric rotation axis. The orbital radius for the spindle is adjustable by rotation of the spindle carrier about the eccentric rotation axis to adjust the offset of the spindle axis.

Abstract: In a thread milling cutter comprising at its tip cutting edges for making a bore, said cutting edges are formed as face milling cutting edges which enclose a mutual angle of 180.degree. or more, so that the thread milling cutter on reaching the intended drill hole depth and in order to be laterally moved need not first be raised. Also, it is possible with the thread milling cutter according to the invention when using said cutter to make threads of any desired diameter with the same thread pitch because the tool tip does not run against the drill hole bottom when laterally moved or offset as with the known thread milling cutter.In addition it is possible with the same tool to provide the thread at the entry with an edge-chamfer in such a manner that impairment thereof by formation of burrs is impossible.

Abstract: In a thread milling tool (1) with a trapezoidal reversible milling plate (3) fixed to a cutter shank (2), the longest edge face (10) on both plate sides (13, 14) is in each case provided with a separate milling edge (11, 12) and an associated chip surface (15, 16), the two toothed milling edges (11, 12) being formed by the same tooth system (21) extending over the thickness of edge face (10).

Abstract: A combined drilling and threading tool comprises a shank having a conical front portion defined by hole-cutting edges, and spirally curved ribs disposed rearwardly of the edges. A row of thread-cutting teeth is disposed along the leading edge of each rib. Each tooth includes a thread-cutting edge facing in the direction of tool rotation, and a side surface extending away from the direction of rotation. The side surface is shaped to produce axial and radial clearance relative to the thread being cut. Each tooth terminates at a location intermediate the leading and trailing edges of its associated rib.

Abstract: A combination tool is disclosed for drilling a hole in a workpiece on the inward feed of the tool and for threading the hole during retraction of the tool. The tool comprises a straight body with a drill point at the forward end, a shank at the rearward end and a thread-form mill between the drill point and the shank.

Abstract: A combination tool is disclosed for drilling a hole in a workpiece on the inward feed of the tool and for threading the hole during retraction of the tool. The tool comprises a straight body with a drill point at the forward end, a shank at the rearward end and a thread-form mill between the drill point and the shank.

Abstract: Method for producing threads and machine tool for thread milling, wherein in order to avoid high cutting speeds and also to produce short millings, a milling cutter is used, which comprises several teeth forming at least one thread, rotates at the point of engagement in the opposite direction to the workpiece, encompasses the latter during the production of an external thread with substantial radial play or in the production of an internal thread is encompassed by the workpiece with substantial radial play, and wherein the advance s of the milling cutter meets the following condition:s=h.multidot.(1-i)with h representing the pitch of the thread to be produced and i the rotational speed ratio of milling cutter and workpiece differing from 1.

Abstract: A machine which orbits an abrader or cleaning tool about a fixed axis at a relatively low speed in which the orbital radius of the abrader may be changed while the machine is in operation.

Abstract: A method for generating a shape on the periphery of a non-rotating workpiece by orbiting a rotating hob in cutting engagement with the workpiece while moving the hob and workpiece relatively lengthwise of the workpiece.

Abstract: A method and apparatus for generating a shape on the periphery of a non-rotating workpiece by orbiting a rotating cutter in cutting engagement with the workpiece. Either the cutter or the workpiece is moved linearly in the lengthwise direction of the workpiece.

Abstract: A combination tool is disclosed for drilling a hole in a workpiece on the inward feed of the tool and for threading the hole during retraction of the tool. The tool comprises a straight body with a drill point at the forward end, a shank at the rearward end and a threadform mill between the drill point and the shank.