Abstract: A centering fastener, a method for manufacturing the centering fastener, a method for using the centering fastener and a wind turbine are provided. The centering fastener includes a connecting body, a buffer lining and a centering member, the connecting body is a columnar body and includes a connecting portion and a non-threaded portion; the buffer lining has a cylindrical shape and covers at least part of the non-threaded portion; the centering member covers an outer surface of the buffer lining, and, at least at a portion corresponding to the buffer lining, the non-threaded portion is separated from the centering member.

Abstract: Osteosynthesis constructs for treating bone fractures and bone screws for use in such systems are disclosed. The bone screws include a threaded front section configured for engagement with cortical bone, a threaded mid-section and an unthreaded neck section configured for limited movement within the near cortex of the bone. Osteosynthesis constructs of the type disclosed promote secondary healing by allowing for substantially parallel motion at the near and far cortex within the effective motion range for callus formation.

Abstract: An integrated locking and sealing fastener with electrical conductivity is revealed. The integrated locking and sealing fastener with electrical conductivity includes a fastener with a surface and a conductive anti-loosening coating. A part of the surface of the fastener is a fastening contact surface and the conductive anti-loosening coating is formed on the fastening contact surface. The conductive anti-loosening coating consists of an anti-loosening portion and a conductive portion mixed with each other. The anti-loosening portion is made from polyamide (PA) resin, acrylic (PMMA) resin, polyethylene, epoxy resin, silicone, rubber, or the combinations. The conductive portion is made from materials including carbon black, metal powders, a silver wire, graphite, or the combinations. The coating on the fastener not only prevents loosening and leakage but also provides electrical conductivity.

Abstract: An electronic device has a heat sink configured to cool an electronic component on a circuit board. The heat sink and the circuit board are joined by snap-fitting.

Abstract: An improved fastening device includes a shank portion with a first end and a second end disposed from the first end. The fastening device includes a head portion disposed adjacent the second end of the shank portion The head portion of the fastening device includes a lower perimeter adjacent the second end of the shank portion, an upper perimeter disposed away from the lower perimeter and a body portion extending between the lower perimeter and the upper perimeter. The head portion is configured to engage a standard hex-shaped socket. The lower perimeter of the head portion has a generally hex shape and the upper perimeter has a different shape than the lower perimeter.

Abstract: A method for making a plated spline nail includes plating an elongated wire with a corrosion resistant material, passing the wire through a forming machine having rollers configured with protrusions formed thereon and extending outwardly therefrom to form grooves in the wire. cutting the wire to a desired length and forming a head, and a point on the wire to form the nail. The nail may have ring shanks formed therein after the head and point are formed. A lubricant may be applied to the nail and/or the forming machine prior to forming the ring shanks and/or prior to passing the wire through the forming machine to form the grooves in the wire. A nail formed by pre-plating the wire, and a nail formed by the method are also disclosed.

Abstract: A progressive former having a bolster and a ram reciprocal towards and away from the bolster, a plurality of workstations evenly spaced across the bolster and ram including aligned tooling piece holders on the bolster and ram, cylindrical die cases in the tooling holders on the bolster and cylindrical tool cases in the tooling holders on the ram, the tooling cases at the workstations being coaxial, a sideways forming mechanism at one of said workstations, the mechanism including a cam and a cam follower radially outward of imaginary outward projections of the associated tooling cases, the cam follower being arranged to be activated by forward motion of the ram towards the bolster, the mechanism including a tool for forming the blank by applying a sideways force on the blank.

Abstract: A bone screw includes an elongate shaft extending longitudinally between a proximal end and an opposing distal end, the shaft bounding a first passageway at least partially extending between the proximal end and the distal end, the shaft being comprised of a radiolucent material. A core is disposed within the first passageway of the shaft, the core being comprised of a radiopaque material. A rounded head or a substantially U-shaped collar is either integrally formed with or is rigidly attached to the proximal end of the shaft.

Abstract: A fastening member for appropriately ensuring strength of a peripheral edge part of a tapered-ring-body-shaped part and appropriately reducing external dimensions. A bolt, a nut or a washer employed for fastening a body is fastened by a screw tightening action The fastening member has a tapered-ring-body-shaped part formed into a ring body shape with a gradually increasing diameter toward a seating surface formed into a circular-planar-band-ring-shape concentric with an axis so as to press against the body being fastened. The taper angle of the tapered-ring-body-shaped part is an acute angle, and an upright surface is formed on an outer circumferential surface of the tapered-ring-body-shaped part and vertically erected from the body being fastened.

Abstract: A rivet bolt in combination with an attachment wherein the rivet bolt includes: a flange having a top surface and a bottom surface, and, a shaft having a threaded portion. An upper cylindrical portion of the rivet bolt includes an upper edge and an interior base surface having a drive head socket. The attachment receives the rivet bolt and comprises: a top surface, a bottom surface, a cylindrical bore therethrough, and an inverted frusto-conical surface extending from the top surface to the cylindrical bore. The upper cylindrical portion of the rivet bolt is deformed and rotatably and slidingly engages the inverted frusto-conical surface extending from the top surface of the attachment to the cylindrical bore therethrough. The upper cylindrical portion of the rivet bolt resides partially within the cylindrical bore. A process for making a rivet bolt in combination with an attachment is disclosed.

Abstract: A fastener system for composite structure providing electromagnetic energy (EME) protection incorporates a fastener having a head with an engagement surface and a shank having a threaded end. A nut is received on the threaded end of the fastener, with the nut also having an engagement surface. At least one of the head engagement surface and the nut engagement surface incorporates a reduced area portion for engagement of a first mating surface or second mating surface, respectively.

Abstract: A method of producing a mine roof bolt includes: providing a plurality of bars of a predetermined length, moving the plurality of bars along a conveyor and indexing the position of the plurality of bars, and passing a portion of each of the bars through a processing station, where the processing station comprises at least one of a header assembly, an extruder assembly, and a threading assembly. The method further includes processing a portion of each of the bars with the processing station. A system for producing a mine roof bolt includes a conveyor configured to index and transport a bar, a feed arrangement configured to continuously deliver bars to the conveyor, a processing station comprising at least one of a header assembly, an extruding assembly, and a threading assembly, where the processing station is positioned along the conveyor and configured to receive and process a portion of the bars.

Abstract: A steel wire for high-strength bolts is used for a non heat-treatment bolt with an excellent cold forgeability for which quenching and tempering steps have been omitted after bolt formation, and which has a tensile strength of 1200 MPa or more and an excellent delayed fracture resistance. The steel wire includes C, Si, Mn, P, S, Cr, Al, N, and B, at least one selected from the group consisting of Ti, V, and Nb with the balance consisting of iron and inevitable impurities. The steel wire has a microstructure wherein ferrite and perlite have a total area rate of 98% or more, perlite lamellar spacing is 250 nm or less, and an area rate of the perlite is more than 40%, and 80% or less. The steel wire has a tensile strength of 1300 MPa or less.

Abstract: A testing method for the bolt to be used under the conditions of excessive wind force by which bolts made of Cr—Mo steel can be separated into a group of bolts usable in cold areas and a group of bolts unusable in cold areas without conducting Charpy impact test involving complicated operation, specifically, a testing method for determining whether bolts made of heat-treated Cr—Mo steel are usable or unusable in cold areas, wherein the determination is conducted on the basis of both J parameter calculated by formula: J=(Si %+Mn %) (P %+Sn %) 104 (wherein P %, Si %, Mn % and Sn % are contents (mass %) of phosphorus (P), silicon (Si), manganese (Mn) and tin (Sn) respectively as disclosed in the inspection certificate of the Cr—Mo steel) and bolt diameter.

Abstract: A process for producing hollow bolts including a longitudinal bore with the hollow bolts being provided with circumferential notches. The hollow bolts are provided with longitudinal grooves extending between elevations determining the bolt diameter, wherein circumferential notches are rolled onto the hollow bolts provided with the longitudinal grooves and the elevations, the longitudinal grooves being of such cross-section that some of the material displaced during rolling-on of the notches flows into the longitudinal grooves.

Abstract: An armor bolt, that is, a bolt in which the bolt head is fabricated from an armor plate and then attached, such as by welding, to a threaded stud or shaft to form the threaded portion of the armor bolt. A preferred embodiment of the invention employs a hex-shaped bolt head cut with a laser or water jet cutter from armor steel plate meeting Mil-A-12560 or Mil-A-46100. The diameter of the bolt head is determined by the hole size in the armor to be attached to the vehicle and the diameter of the threaded stud or shaft. The thickness or height of the bolt head is dictated by the ballistic threat it needs to stop. The threaded shaft in a preferred embodiment is resistance welded to be perpendicular to the head at the center of one face of the hex head.

Abstract: A welding stud including a head and a shank extending from the head. The shank has an end region opposite the head and the end region includes at least two angled surfaces which incline towards an axis of the shank in a direction moving away from the head.

Abstract: A set of tooling for making pointed headed bolts of a given diameter in numerous lengths with roll thread ready threaded to the head and partially threaded shanks in a four forming station forming machine, the tools being configured to work on wire stock as received at the first station of a diameter larger than or substantially the same as the roll diameter and not greater than the nominal diameter of the bolt, including at least two sequential head forming tools for mounting on the slide, an extrusion pointing tool for mounting on the die breast, a roll diameter extrusion tool for mounting on the die breast and a head support tool mountable in a station on the slide at multiple axial positions corresponding to standard lengths of the bolts being made, the head support tool being arranged to work at either the extrusion pointing station or the roll diameter extrusion station.

Abstract: The production method according to the invention for creating a thread in an elongated semi-finished product comprises the following steps: shaping, especially lengthwise rolling, of at least two lengthwise grooves into a blank and lengthwise rolling of a thread into the areas circumferentially delimited by the grooves. The distance from the beds of the grooves to the axis of the blank is smaller than the distance from the root of the thread to the axis.

Abstract: Embodiments of the present invention comprise methods and apparatuses for manufacturing dual-threaded bolts. The invention comprises utilize rolling dies having one die with coarse thread projections over a surface of the die and fine thread projections over another surface of the die. In some embodiments, the surfaces on which the coarse thread projections and the fine thread projections are located are distinct from one another, or in other embodiments a portion of the surfaces may overlap or be formed integrally within the other projections. In some embodiments a portion of, or all of, the coarse thread projections may be located on a first die section piece while a portion of, or all of, the fine thread projections may be located on separate second die section piece (e.g., an insert) that is operatively coupled to the first die section piece.

Abstract: Threaded structures such as threaded standoff structures may be provided with features that control the flow of solder. A base structure for a standoff may be formed from a material such as metal. During attachment of the standoff to a substrate such as a printed circuit board, the base structure may be exposed to molten solder. A solderphilic coating may be provided on the outer surface of the standoff to encourage wicking of solder up and over lower portions of the standoff and beneath the standoff, thereby helping to secure the standoff to the substrate. The center of the base structure may be provided with threads to receive screws. To prevent solder from covering the threads, the surface of the threads may be provided with a solderphobic surface.

Abstract: A thread forming screw having a minimum surface hardness of HRC 56. The screw can form threads in a workpiece having a surface hardness which exceeds HRC 23. A method of surface hardening a screw includes carbon enriching the screw to at least a 0.48 carbon level, and then quenching the screw. Then, the screw is tempered such that the surface hardness does not exceed the core hardness by more than 3 Rockwell C points, and both the surface and core are at a Rockwell C33-C39 hardness. Subsequently, the point is induction hardened, and the screw is quenched again. The screw is again tempered such that the lead threads and the first 3-4 full threads are at a Rockwell C56 minimum hardness, preferably to a depth of at least 0.008 inches, and the core of the fastener is at Rockwell C33-C39 hardness. Finally, a finish is applied.

Abstract: The present invention includes a rock bolt having a longitudinally expandable tube. The tube includes a longitudinally extending depression that defines a temporary enclosed longitudinal passageway. The rock bolt further includes a shielded distal end to prevent debris from entering the temporary enclosed longitudinal passageway. The distal end is shielded using a cover which may be a plug or a cap and may provide a rounded tip for the rock bolt. The plug may be spherical. The cap may be attached such that its proximal end abuts the distal end of the rock bolt, is inserted into the distal end of the rock bolt, or extends beyond the distal end and along the sidewall of the rock bolt. The present invention also includes a method of making such a rock bolt and a method of using such a rock bolt.

Abstract: A wind turbine installation comprises anchor bolts having a sheath or sleeve which extends above the cement foundation and the overlying grout layer. If desired, the sleeve may partially extend inside the base flange of the wind turbine tower. The sleeve may be manufactured from polypropylene, polyethylene or other materials having satisfactory mechanical properties, primarily that the material be capable of withstanding sufficient plastic deformation to cause the material to conform to the shape of the threads of the anchor bolts without the material failing. This swaging operation results in a crimped end which forms an interference fit with the threads of the anchor bolt thereby preventing or limiting the intrusion of water or other liquids into the bolt-sleeve annulus during the installation of the turbine foundation.

Abstract: A threaded fastener includes a shank having a first, threaded portion and a hardened thread portion. The shank includes a thread extending outwardly from a shank body over a first length of the shank. A second portion of the shank includes a groove positioned coincident with the thread and including a turn ratio equal to a turn ratio of the thread. The shank comprises corrosive resistant stainless steel. A coil of hardened steel engages the groove to fill the groove along the second portion.

Abstract: A retainer for limiting the rotational movement of a polygonal bolt part during tightening of a bolt is provided. The bolt part includes a bolthead or a nut. The which retainer includes a cavity dimensioned to accommodate the bolt part and includes side walls comprising a number of crests extending into the cavity and corresponding to side faces of the bolt part such that the rotational movement of the bolt part positioned in the cavity is limited by contact made between at least one side face of the bolt part and a corresponding crest of the cavity. Also disclosed is a method of limiting the rotational movement of a polygonal bolt part during tightening of a bolt, a method of manufacturing such a retainer, and the use of such a retainer.

Abstract: A threaded bolt may be produced according to a method including the steps of: forming a cylindrical bolt blank of metal with a root end and a head end, and with a section of the bolt blank adjoining the root end that is reduced in diameter up to a region designed for the formation of lead-in flights. Then, in a first rolling phase, partially form the principal thread flights and the lead-in thread flights using a first pass of flat jaws of a thread rolling machine. Then, in a second rolling phase, fully form the principal flights and the lead-in flights and forming grooves.

Abstract: A method of manufacturing fastenings or fasteners with radial outer contours, especially screws or threaded bolts, made of solid metal is performed by a device. The method manufactures the fastenings or fasteners preferably on a multi-stage press. Several recesses running in an axial direction at a fixed radial distance are formed in the shank-shaped section of a blank. The prefabricated blank with the recesses is inserted into a multi-part split mold within a multi-stage press, whose die stocks have an inner profiling forming the outer contour, and are opened in the starting position, that at the places where the die stocks are opened, there are the recesses. During the closing movement of the die stocks, at least one radial outer contour is pressed on the shank-shaped section of the blank by radial action of forces, with the recesses preventing material from getting between the die stocks during the pressing process.

Abstract: A threaded bolt having a shank of basic cylindrical form and with a root end and a head end is provided with a spiral-shaped external thread, which has at least one principal flight and in the vicinity of the root end has at least one lead-in flight, adjoined by the principal flight, where the lead-in flight has a lead-in surface which differs from the principal flight and is formed in order to come into crossing-free engagement with flights of a complementary internal thread of an element. The lead-in flight and the principal flight are interrupted by at least one groove, which extends in the longitudinal direction of the shank in order to form a free space for the accommodation of lacquer residues. The flights and the grooves are initially formed by rolling.

Abstract: A roof bolt comprises a shaft for insertion in a hole drilled in a mine roof and a head whereby the bolt may be rotated, the head being offset with respect to the longitudinal axis of the shaft so that when the bolt is rotated by means of its head the shaft is caused to describe a circle of greater diameter than its own diameter, and where the offset is at least 08 inch and not more than 0.25 inch. Preferably the offset is from 0.10 to 0.16 inch. The invention includes a method for the production of roof bolts which comprise a shaft for insertion in a hole drilled in a mine roof and a head whereby the bolt may be rotated, the method being characterised by being controlled so that at least 90% of the bolts produced have their head central axis offset with respect to the longitudinal axis of the shaft by an amount of at least about 0.08 inch and not more than about 0.25 inch.

Abstract: A process for the formation of a thread form in a substantially elongate member (1), wherein the thread form includes at least one rib (3) spaced apart from at least one other rib along the elongate member and wherein the thread form has a relatively coarse rib spacing but a fine thread pitch.

Abstract: A fastener is described having a head formed with a recess which accommodates a square head driver, symmetrical drivers, such as PHILLIPS™ style drivers, asymmetrical style cross head drivers, such as POZIDRIV® style drivers, and combination square and cross drivers without compromising performance of the drivers.

Abstract: The object of the present invention is to prevent the encroaching and the seizure between the bolt and the female screw caused by an oblique screwing of the bolt into the female screw when the bolt and the female screw are fastened together. Another object of the present invention is to manufacture the bolt in a low cost, by using said bolt, the encroaching and the seizure between the bolt and the female screw caused by a oblique screwing of the bolt into the female screw are certainly prevented. Said objects may be attained by a bolt consisting of a column part and a polygonal pillar part extending from an end of said column part wherein a complete thread is formed on said column part and a screw blade continuing to said complete thread is formed on said polygonal pillar part.

Abstract: A method of making a UHMWPE body combined with a bolt, a cap screw, a reinforcing member uses a compression molding machine equipped with a male and female mold set. Particulate UHMWPE dispensed into the cavity of the female mold surrounds the head of the bolt and screw and reinforcing member. Pressure and heat applied to the particulate UHMWPE molecularly bonds the UHMWPE to the bolt, screw, and reinforcing member.

Abstract: A Nitinol element is threaded by first heating it to a temperature of about 800° C., and then applying a threading tool, such as a tap or die, to form the threads. Nitinol has a unique property of increasing yield strength as cold work is applied, but this property ceases to exist above a temperature of about 800° C. The strength of the material at this temperature, however, is sufficient to resist the torque applied by a threading die being screwed onto a Nitinol blank even though it is low enough to permit the Nitinol to flow when the cutting threads of the threading die are forced into the material. At this temperature, the Nitinol is not actually cut by the cutting threads of the tap, die or other threading tool, but instead, the material flows around the cutting threads to form threads in the Nitinol.

Abstract: A threaded fastener lighter in weight and easier to produce is made by the moderate temperature-forging, from a raw magnesium material that contains microcrystals whose diameter is about 100 &mgr;m or less. The raw material may be pure magnesium of industrial grade in one case, and alternatively be any magnesium alloy or such a composition as comprising as its matrix the alloy or pure magnesium, in the other cases. The raw material has a superplastic property and a fine-granulated metallographic internal texture, and when making the fastener, will be heated to 250-400° C. at which superplasticity takes place to facilitate the forging to form the fastener. A method proposed in the invention to make the fastener is thus such that the number of necessary processing steps is reduced and manufacture cost is lowered.

Abstract: A method for heat treating a metal article such as a fastener comprising the step of case hardening the fastener in a gas carborizing atmosphere at a temperature of about 1700° F. or in a carbonitriding atmosphere at a temperature of about 1550° F., and quenching the fastener in water or oil and tempering the fastener at a minimum temperature of 770° F. for approximately one hour.

Abstract: In a first embodiment, a method for forming a hardened fastener having a hardened fastener head. Alloys made of cobalt, nickel, chromium, and molybdenum have very high hardnesses while maintaining ductility. Metals conforming to the chemistry of AMS 5844 and AMS 5842 are disclosed as the preferred materials. These hardnesses are also maintained at high temperatures. In order to form a head upon such materials, a fastener blank is first initially hardened by cold reduction twenty to thirty percent (20%-30%). A fastener head is then formed in the fastener blank by additional cold forging. The remaining shank portion of the fastener blank is cold worked in a third process with the entire three-part cold forging process cold reducing the material forty-eight to fifty percent (48%-50%). Additional hardness may be obtained by heating the material in a temperature range between ca. 1200.degree. F. and 1300.degree. F.

Abstract: A method of forming an apparatus having a captured washer includes the step of forming a shaft with a first end, a second end, a shaft diameter, and an axis. A stop element is provided on the shaft. An integral washer is formed on the shaft spaced from the stop element. The washer has a thickness and a diameter greater than the shaft diameter. The washer extends generally perpendicular to and radially outward from the shaft. The washer has a first surface facing the stop element and opposite surface facing opposite the first surface. A button is formed on and extends axially from the washer opposite. The button has a diameter greater than the shaft diameter and less than the washer diameter. A groove is formed into the first surface of the washer and defines a washer opening having an inside diameter less than the button diameter. The groove is formed so that the washer remains attached to the button by a material bridge extending between the button and.

Abstract: An axially-extendable-bolt forming process by upsetting includes preparing a die having a through bore, and an internal upsetting cavity and a buffer space, a rod-shaped bolt precursor and a knock-out member, primarily pressing a leading end of the bolt precursor onto a leading end of the knock-out member, and secondarily pressing the bolt precursor onto the knock-out member. In the preparing step, the bolt precursor and knock-out member are fitted into the through bore of the die so that they can be brought into contact with each other. In the primarily-pressing step, the leading end of the bolt precursor is swollen finely and is brought into contact with an inner peripheral surface of the through bore of the die so that an excess material, being present adjacent to a leading-end surface of the bolt precursor, is flowed out into the buffer space.

Abstract: In a process for forming a bolt, a die, a rod-shaped knock-out member, and a punch are prepared. The die has opposite end surfaces, a through bore opened to one of the opposite end surfaces, and a space connected with the through bore and disposed substantially perpendicular to an axial line of the through bore. The knock-out member is disposed in the through bore. The punch is disposed so as to face one of the opposite end surfaces of the die to which the through bore is opened. A bolt precursor is fitted into the through bore of the die at the leg member, and is pressed by the punch at the head member. The leading end of the leg member is pressed by the knock-out member, and accordingly an excess material of the bolt precursor at around the leading end of the leg member, or an excess material thereof adjacent to the leading end of the leg member is deformed and flowed into the space of the die as a thinned-out portion. Thus, the bolt precursor can be flattened at the leading-end surface of the leg member.

Abstract: A fastener system includes a fastener and a driver tool in which the fastener includes a cavity for insertion of the driver tool and in which the driver tool and the fastener form an interlocking relationship between the driver tool and the fastener is formed by having a portion of the fastener overlie a portion of the driver tool. This interlocking relationship prevents accidental separation of the driver tool from the fastener and consequent marring of the surfaces of the work pieces being joined together and also prevents stripping of the driver tool and the fastener cavity.

Abstract: The present invention relates to a burred fastener for forming a friction fit between the fastener and a driver. The friction fit retains the fastener in contact with the driver during insertion, tightening and loosening of the fastener into a work surface. Burrs are formed in the inner side surfaces of an indentation or slot formed in the fastener head. A method for forming the burred fasteners includes striking the screw head with a deformation object.

Abstract: In a method of making an elongate object (49) with a head at one end and a point at the other end, a blank (49) is placed in a die (50) having a through-going channel, following which the head end is subjected to axial pressure by a tool (52), while a stop member (55) is kept engaged with the die (50) at its other end. A pre-formed head is initially provided on the blank (49) so that the head has an excess of material with respect to the size of the final head. A cavity (56) is formed in the stop member and is in extension of the through channel. When blank (49) is subjected to axial pressure the tool (52) causes flow of material in the shank of the blank (49) so that blank material flows into the cavity (56) of the stop member.

Abstract: Apparatus and methods for forming a thread of varying pitch by utilizing a threading assembly which includes a plurality of threading elements having thread cutting or forming portions on the different elements for engaging the work piece at different locations, with the assembly and work piece being driven both rotatively and at the same time axially relative to one another to form the thread. The rate of axial advancement per revolution between the work piece and each of the threading elements is varied, and the elements of the assembly are also shifted axially relative to one another during the rotary and axial movement, to give the thread its varying pitch.

Abstract: Disclosed is a method of forming a shaped configuration by cold forging at an end of a long element, such as the armature shaft of a starter motor for an automobile. The die used in this method has an inner space in which a section for forming the shaped configuration is provided at one end portion thereof, and the diameter of the inner space gradually increases from the shaped configuration forming section to the other end portion of the inner space. A material is placed in the die from the other end portion of the inner space and, then, is forced into the die by a punch to be forged into the shape corresponding to that of the inner space of the die. After the forging, the shaped material is pushed out of the die by a knock-out pin which is inserted into the die in the opposite direction to the direction in which the material is forced.

Abstract: This invention is a manufacturing method of Austenitic stainless steel self-tapping and self-drilling screw. It uses low carbon steel or low carbon alloy steel and forges or cuts it into a round rod with a shoulder, non-threaded bolt, and drilling end portion. After it is carburized and properly heat-treated, it will be welded together with an Austenitic stainless steel round rod which has a non-threaded bolt. And then the welded flush and shoulder will be cut so that a non-carburized hardened area in a proper width can be formed. Lastly it is threaded and quenched so as to manufacture a screw whose head and threaded stem joint are high corrosion-resistance and whose carburized drilling end portion has a high self-tapping and self-drilling function.

Abstract: A fastener which includes a threaded pin having a notched helical thread to receive a threaded collar which, after being set to a torque, is deformed to move material into some notches on the thread to form a lock to prevent unthreading. The notched thread can be formed by a three-section roll die, the first section of which forms the thread, the second of which notches the thread, and the third section of which smoothes the thread. The invention comprehends the die, the die forming method, the pin, the pin and collar, and a joint formed with the pin and collar.