Abstract: A method for producing a ball raceway on a workpiece includes providing the workpiece, machining a preliminary thread profile on the workpiece and providing a thread rolling tool. The thread rolling tool has a tool shank, and the tool shank has a free end with a tool head having a roller profile. The method also includes clamping the workpiece into the thread rolling tool, rotating the workpiece about an axis of rotation, moving the tool shank longitudinally along the workpiece, and rolling the roller profile on the preliminary thread profile to generate a final thread profile.

Abstract: A one-piece stud and clip is provided by a process working sheet material into a monolithic stud and U-clip fastener. The process includes forming an elongated stud from the sheet material, and bending the sheet material to form the clip. The stud can be a rolled cylinder of the sheet material, or an uninterrupted stud drawn from the sheet material.

Abstract: A continuous strip of T-Nuts formed on a common strip of metal. Each T-Nut of the strip of T-Nuts is integrally connected to the next adjacent T-Nut by carry tabs. The carry tabs can be frangible themselves or contain a frangible portion. Each T-Nut includes a cylindrical bore therein and a threaded interior. A mechanism feeds and severs the endmost T-Nut in endwise fashion. The mechanism to feed and sever the endmost T-Nut includes a cutting blade positioned vertically below the frangible portion of the carry tab. A shearing ram having a guide positioned axially in line with the cylindrical bore in the endmost T-Nut is adapted to move vertically from an upper to a lower position to engage the cutting blade with the frangible portion and sever the endmost T-Nut.

Abstract: The present invention is an assembly line for continuously manufacturing self-attaching fasteners from a metal rod having a predetermined profile. The self-attaching fasteners are joined together with wires and reeled onto spools for use at a secondary installation site. More importantly the invention is an improved streamline method and apparatus which produces burr-free self-attaching fasteners, without deformation, and joins the self-attaching fasteners and wires together within a die press.

Abstract: A method of manufacturing a nut in a screw and nut system comprises a first material removal stage to form an internal thread of which the value of the nominal diameter is lower than a predetermined final nominal diameter value and a second plastic deformation stage of the thread formed during the first stage to obtain the predetermined final value by material displacement.

Abstract: The invention relates to a method for producing hollow body elements (200), for example, nut elements which are applied to components which are normally made of steel (280), in particular, for producing hollow body elements having an essentially quadratic or rectangular external profile (202). Said method consists of cutting individual elements of a profile in the form of a profile rod (1) or a winding after holes (204) have previously been stamped in the profile, a threaded cylinder (206) is subsequently, optionally, formed using a follow-on composite tool (10) which consists of several working stations. The invention is characterized in that a penetrating process and a punching process are carried out in the working station. The invention also relates to hollow body elements (200), components, follow-on composite tools (10) and rolling mills (600, 602).

Abstract: 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 solderphobic material such as brass. A through hole may be formed in the base structure. The base structure may be coated with a solderphilic material such as an inner layer of nickel and an outer layer of tin. A tapping tool may be used to remove the solderphilic material from the opening by tapping threads into the opening, thereby exposing the underlying base metal of the standoff in the opening. During attachment to a substrate such as a printed circuit board, the standoff may be exposed to molten solder. The solderphilic coating on the outer surface of the standoff may attract the molten solder, whereas the solderphobic base metal in the threaded opening may help prevent solder from contaminating the threads in the opening.

Abstract: An anchor bolt locator is provided that is inexpensively manufactured on automatic die-press machines from sheet steel and a structural nut that does not require any welding, while also being easy to use and install with current, commonly-used building practices and anchor designs. The anchor bolt locator is made from a galvanized sheet metal chair and a structural nut attached to the chair by way of a friction fit.

Abstract: In order to optimize a nut and a method for the production of a nut, comprising a nut body which is provided or can be provided with an internal thread and has a polygonal section with a polygonal outer contour which has, on the one hand, edge areas and, on the other hand, key faces which are located between the edge areas and extend in key face planes extending in a manner conforming to standards, in such a manner that it has mechanical properties which are as ideal as possible with as low a weight as possible, it is suggested that the nut body have a plurality of recesses which extend into the nut body in the direction of the bore proceeding from the respective key face planes.

Abstract: The present invention provides a method for manufacturing a fitting that has a configuration where a fitting plate and a blind nut are integrally formed and also provides a tap tool for use in this method. According to the present invention, performing tap processing to an internal diameter portion to integrally form a portion corresponding to the blind nut, when a tap tool having a protrusion at an end thereof is utilized to be inserted into the bag-like blind hole at a planned part of the blind nut and the tap processing is carried out, the protrusion provided at the end of the tap tool comes into contact with an inner wall at the end of the bag-like blind hole, and a pressed material thereby forms a convex shape on an outer side of the bag-like blind hole.

Abstract: The present invention is premised upon method of manufacturing rolled pierce nuts having a predetermined profile from a metal rod, more particularly to a method and apparatus delivering greater manufacturing flexibility through the use of multiple stations with flexible inputs and outputs.

Abstract: Cage nut having a cylindrical nut body (14) provided with a coaxial bore having an interior thread, wherein the nut body is ending in an rectangular plate (16) and, wherein the nut body (14) by means of the rectangular plate (16) is floatingly supported within a cage (12) and, wherein the entire cage nut (10), i.e. the nut body (14), and the cage (12) merely is manufactured from a single strip (100) of metal sheet by tube-forming, thread-cutting, bending and punching as well as a method for producing such a cage nut.

Abstract: A spacer nut manufacturing method which does not use a NC lathe and which allows machining using existing press working equipment, involves a low parts supply cost, and which helps to achieve a high production efficiency at a low production cost is disclosed. The method of manufacturing a spacer nut arranged between a casing and a board arranged inside the casing and serving to fix the board in position while keeping the board spaced apart from the casing by a predetermined distance dimension is presented.

Abstract: The invention relates to a functional element in the form of a press-in element for attachment to a sheet metal part, wherein the functional element has a head part and a shaft part, the head part has a ring-shaped sheet metal contact surface at the side adjacent the shaft part and a ring-shaped axial recess inside this ring-shaped sheet metal contact surface and surrounding the shaft part at the transition from the head part into the shaft part. In accordance with the invention the shaft part has a plurality of circumferentially distributed radial recesses extending in the axial direction and between these noses which likewise extend axially and project radially, wherein raised material portions are present at the positions of the radial recesses at their axial ends adjacent the head part and form undercuts with the head part in the region of the ring-shaped recess.

Abstract: A continuous strip of T-Nuts formed on a common strip of metal. Each T-Nut of the strip of T-Nuts is integrally connected to the next adjacent T-Nut by carry tabs. The carry tabs can be frangible themselves or contain a frangible portion. Each T-Nut includes a cylindrical bore therein and a threaded interior. A mechanism feeds and severs the endmost T-Nut in endwise fashion. The mechanism to feed and sever the endmost T-Nut includes a cutting blade positioned vertically below the frangible portion of the carry tab. A shearing ram having a guide positioned axially in line with the cylindrical bore in the endmost T-Nut is adapted to move vertically from an upper to a lower position to engage the cutting blade with the frangible portion and sever the endmost T-Nut.

Abstract: The present invention is an assembly and method for continuously manufacturing fasteners. A die press actuated at a first speed receives the contoured wire into a die having a piercing element for piercing an aperture and a cutting element for cutting a fastener from the wire. A guide receives the fasteners from the die press and a drive unit engages the fasteners oriented by the guide and conveys the fastener to an elevated height relative to a tapping device. The guide redirects the fasteners by a first router. The fasteners are gravity fed into the first router and redirected to one of the tapping devices. Each tapping device has a tapping element for forming internal ribs in the aperture of the fastener. The tapping devices each actuates at a second speed that in aggregate is generally equal to the first speed of the die press.

Abstract: The invention relates to both nut assemblies and methods for producing the same. Said nut assemblies consist of a nut body (1a) and a pressure disk (2a). The nut body has a drive portion, such as a polygonal portion, for engaging with a tool and an abutment region that can be brought into contact with the supporting surface of the pressure disk arranged on the nut body in a captive manner. The pressure disk has a central opening into which a neck formed on the nut extends axially at least in part. The neck has a projection for forming a captive connection. This projection radially overlaps or engages the thrust ring.

Abstract: Cage nut having a cylindrical nut body (14) provided with a coaxial bore having an interior thread, wherein the nut body is ending in an rectangular plate (16) and, wherein the nut body (14) by means of the rectangular plate (16) is floatingly supported within a cage (12) and, wherein the entire cage nut (10), i.e. the nut body (14), and the cage (12) merely is manufactured from a single strip (100) of metal sheet by tube-forming, thread-cutting, bending and punching as well as a method for producing such a cage nut.

Abstract: An assembly line for continuously manufacturing fasteners from a rod with a groove for receiving a wire for retaining the fasteners in a strip includes a receiver for receiving the rod. A die press is arranged to receive the rod from the receiver and includes a piercing member for piercing an aperture in each fastener and a cutting member for cutting each fastener from the rod. A tapping member provides ribs to an inner wall of the aperture formed in the fastener by the piercing member. An inspector inspects the internal rib formed into the inner wall of the aperture disposed in the fastener verifying exactness of the aperture and the rib. A wire inserter inserts the wire into the groove forming a strip of connected fasteners. The inserter receives the fasteners sequentially from the inspector after verification of the exactness of the aperture disposed in each fastener.

Abstract: A manufacturing method of weld nut made of stainless steel plate capable of manufacturing a weld nut of a small size generally known as a micro-screw of thin type and nominal thread diameter of about M1.6 easily by blanking and processing a stainless steel plate, and a blanking punch to be used in this manufacturing method. The manufacturing method of weld nut made of stainless steel plate includes a step of blanking and processing a tap drill hole 22 in a stainless steel plate material 20 having a thickness nearly equal to the height of the nut, a step of forming a nut main body 23 by blanking a nut outer shape in the material 20 around the tap drill hole 22, and simultaneously forming a plurality of weld protrusions 24 in the outer circumference of the bottom of the nut main body 23, and a step of processing female threads 25 in the inner circumference of the tap drill hole 22 of the nut main body 23.

Abstract: A method of forming pierce and clinch nuts by rolling a section having the desired cross-section, punching equally spaced bores through the central pilot portion and then punching configured openings through the central pilot portion having convex arcuate surfaces and eliminating sharp corners. The strip of interconnected self-attaching fasteners may be installed directly from the strip in a panel, fed in bulk or separate fasteners interconnected by frangible connectors. The resultant self-attaching nut includes a central pilot portion having a bore through the top face, integral flange portions extending from opposed sides and the pilot portion includes convex arcuate faces reducing or eliminating stress cracking and propagation of stress cracks.

Abstract: Disclosed is a method for producing hollow elements (200), such as nut elements, which are to be mounted on parts generally made of sheet metal, particularly for producing hollow elements having an at least substantially square or rectangular outer contour (202). According to said method, individual elements are cut to size from a profiled member that is provided in the form of a profiled bar or a reel after punching holes into said profiled member, optionally followed by embodying a threaded cylinder (206) using a follow-on composite tool (10) with several workstations (A, B, C, D). The inventive method is characterized in that a penetrating process, a punching process, and a flattening process are carried out in the workstations (A, B, C, D). Also disclosed are hollow elements (200), assembly pieces, and a follow-on composite tool (10).

Abstract: The method of forming self-attaching female fasteners by rolling a continuous metal strip including a central pilot portion having parallel sides and flange portions on opposed sides, severing at least the pilot portion and cold forming the rectangular pilot portion into a cylindrical end portion. Wing-shaped radial portions are formed in the pilot portion which may be severed or remain for anti-rotation features. The strip may remain continuous, wherein the severed pilot portions are spread and the flange portions are thinned or the strip may be severed into discrete fasteners. The female fasteners thus include generally cylindrical pilot portions and rectangular flange portions which may include rolled grooves.

Abstract: There is provided an insert nut comprising a hollow shank in a polygonal shape. A metal plate is provided. The metal plate has a first region. The first region has a rectangular shape having a horizontal direction and a vertical direction. The first region is pressed to form a plurality of convexes discontinuously aligned. The convexes are not formed at bend strips parallel to the vertical direction. The press process can be done by using, e.g., a die and a punch. The first region is bent at the bend strips to form a hollow shank. Thereby, the convexes serve as a female screw on an inner surface of the hollow shank. The hollow shank of the present invention has a cross section at a face perpendicular to an axis of the hollow shank. The cross section is polygonal.

Abstract: An assembly line for continuously manufacturing fasteners from a rod with a groove for receiving a wire for retaining the fasteners in a strip includes a receiver for receiving the rod. A die press is arranged to receive the rod from the receiver and includes a piercing member for piercing an aperture in each fastener and a cutting member for cutting each fastener from the rod. A tapping member provides ribs to an inner wall of the aperture formed in the fastener by the piercing member. An inspector inspects the internal rib formed into the inner wall of the aperture disposed in the fastener verifying exactness of the aperture and the rib. A wire inserter inserts the wire into the groove forming a strip of connected fasteners. The inserter receives the fasteners sequentially from the inspector after verification of the exactness of the aperture disposed in each fastener.

Abstract: The invention relates to a method for producing hollow bodies (11, 211, 411) such as nut elements to be fastened to components (13, 213, 413) that usually consist of sheet metal. The invention especially relates to a method for producing hollow bodies with an at least substantially square or rectangular outline by cutting individual bodies from a profile (10, 210, 410) in the form of a profile rod or a reel after respective holes (98, 298, 498) have been punched into the profile, and optionally afterwards producing a threaded cylinder (110, 310, 510). The inventive method is further characterized in that before or after the punching of the profile a passage treatment is carried our in order to produce a cylindrical or annular projection (36, 236, 436), concentric to the punching or the intended punching, on the side (12, 212, 412) of the profile facing the component by flow of material. The projection is optionally shaped to an annular punched section in an additional molding cycle.

Abstract: The locking nut and bolt system includes an elongated locking unit, mounted in a nut and operative with a specially configured groove bolt. The locking unit includes a plurality of at least three tines, asymmetrically located, which protrude tangentially and generally radially inward. The tines are radially asymmetrically disposed such that when a respective tine latches into a corresponding groove, asynchronous locking operation is achieved. When the tine is engaged in the groove, counter-rotational movement (loosening) is prohibited. In another embodiment, the locking unit has different sized edge cut-outs prohibiting the locking insert from rotating within the nut. The locking unit may also include a longitudinal split and a key and a keyway. A manufacturing process is also disclosed.

Abstract: An assembly line for continuously manufacturing fasteners from a rod with a groove for receiving a wire for retaining the fasteners in a strip includes a receiver for receiving the rod. A die press is arranged to receive the rod from the receiver and includes a piercing member for piercing an aperture in each fastener and a cutting member for cutting each fastener from the rod. A tapping member provides ribs to an inner wall of the aperture formed in the fastener by the piercing member. An inspector inspects the internal rib formed into the inner wall of the aperture disposed in the fastener verifying exactness of the aperture and the rib. A wire inserter inserts the wire into the groove forming a strip of connected fasteners. The inserter receives the fasteners sequentially from the inspector after verification of the exactness of the aperture disposed in each fastener.

Abstract: Cold extrusion procedures for obtaining metal elements such as for example bushings, nuts or other elements with dead or through holes, screws, standard and special shape extruded or pressed products, etc. on a machining center comprising a series of hydraulic presses connected to each other with an automatic movement system. The final drilling or shearing of the elements is advantageously carried out by a dedicated drilling or shearing unit, working at high speed, which can consist of a vertical mechanical press. The use of the plant comprising several hydraulic presses together with the rapid drilling or shearing unit makes it possible to achieve a high level of productivity.

Abstract: A section (10; 110) is provided for the manufacture of hollow body elements, in particular for the manufacture of pierce and rivet nuts having a square or rectangular outline in plan view and a ring-like piercing section (36; 236) at a side confronting a component consisting of a sheet metal material or the like. The section (10; 210) is at least substantially rectangular in cross-section with two bars (14, 16; 214, 216) at the side (12; 212) later confronting the component. The bars are spaced apart and extend parallel to the longitudinal sides (18, 20; 218, 220) of the section, are likewise at least substantially rectangular in cross-section and form, in the finished element (11, 211), a feature providing security against rotation. The bars respectively each have an inclined flank (68, 70; 268, 270) at the inner side which forms an undercut (69, 71; 269, 271).

Abstract: A method of manufacturing hollow body elements such as nut elements for the attachment to components consisting normally of sheet metal, in particular to the manufacture of hollow body elements with an at least substantially square or rectangular outer periphery by cutting individual elements by length from a section present in the form of a bar section or a coil after prior punching of apertures in the section, optionally with subsequent formation of a thread cylinder, utilizing a progressive tool having a plurality of working stations in which respective processes are carried out is characterized in that in each working station two respective operations are carried out for the section, or for each of a plurality of sections arranged alongside one another, for each stroke of the progressive tool at the same time. A hollow body element and also a progressive tool are also claimed.

Abstract: The present invention is to avoid the flange portion of a T-nut of from overlapping the portion between the claws of another T-nut, while the T-nut is supplied on a supply track provided on a nut applying machine, and also to engage the projections formed between the claws into a fixing material when the T-nut is knocked into the fixing material. There is provided a T-nut formed of a metal material in an integrated manner, having a shank portion 49 and an octagonal or almost octagonal flange portion 50, and two pairs of claws 55 to 58. The shank portion 49 has a caulking portion 51 and a female screw portion 52. The caulking portion 51 is formed thinner than the female screw portion 52. Projections 64, 65 are provided between each of the pairs of claws, formed by bending convex portions integrally formed with the flange portion 50 toward the second end of the shank portion 49.

Abstract: A method of cold forming a self-attaching female fastener (20) which includes deforming a fastener blank (120) having an annular pilot, (122) an annular flange (128) surrounding the pilot and a groove (132) in the flange having cylindrical walls and annular protrusions (152, 154) on the flange and pilot, then deforming the protrusions toward each other to form an annular re-entrant groove (32) having relatively inclined arcuate walls.

Abstract: Method for the production of a spindle nut (3) of a spherical thread drive mechanism, whereby the spindle nut (3) has at least one screw-shaped track (4) formed as a single piece on its inner circumference, whose threads (38) are limited by shoulders (6). The shoulder (6) is interrupted by a deflecting recess (23) at at least one deflecting position, in order to deflect balls (13) out of one thread into an adjacent thread (38). The method includes locating a tool arbor (56) in a hollow blank (57), whereby the tool arbor (56) has on its outer circumference a counter profile of the screw-shaped track (4) and a projecting part (59) for each deflecting recess.

Abstract: A raw parallelepiped metal piece is pressed into a closed mold to provide a nut blank that has a generally square pilot portion (14) for piercing a metal panel, the nut blank having a pair of flanges (16) that continue from opposite side walls (15) of the pilot portion. Then, the nut blank is coined to form ridges (20) extending along and integral with opposite upper edges of the side walls (15), before pressed within an open mold so that the ridges are swaged out sideways to form shoulders (21). A lateral groove (22) is defined between below each shoulder and in the side wall. A rough bore (23) will be formed axially through the pilot portion (14), before tapped to have a female thread (24) in the inner periphery of the bore.

Abstract: A method of forming a female fastener including rolling a body portion strip having a midportion and flange portions on opposed sides of the midportion, piercing spaced openings through the midportion, cutting the strip to length between the openings, cold forming a separate generally cylindrical pilot portion having a length greater than the width of the midportion and a diameter greater than the opening through the midportion, preferably including radial splines, and press fitting the pilot portion through the opening in the midportion. The self-attaching female fastener thus includes a rectangular body portion and a generally cylindrical pilot portion having an end face spaced above a plane of the midportion and may be formed of a harder metal than the body portion.

Abstract: A manufacturing process of a clinch nut consists in forming a recess zone in a rough casting by cold heading so as to obtain a rough part. The rough part then undergoes a thermal annealing treatment followed by a cold heading operation enabling a bore to be formed designed to contain an internal thread. The internal thread is preferably achieved by tapping by upsetting material from the bore of the nut.

Abstract: An elongated T-nut fastener is formed from a single piece of material. The fastener includes a barrel and a flange, with a threaded portion in the barrel and an unthreaded portion beyond the threaded portion. Fastening sites are provided at spaced locations along the length of the fastener.

Abstract: A method for manufacturing cold-forged wing nuts is to have a column linear material rolled and compressed into lots of column material units connected continuously and then receiving the steps of shearing, flattening, compressing and trimming, punching, wing forming and threading, able to produce wing nuts with quickness and with less waste material, and also having standardized specifications and high strength as well as property of corrosion resistance. Besides, one more step of forming insert grooves is added between the step of flattening and the step of compressing and trimming, so that the column with wings material unit can be formed with insert grooves, and after finishing the steps of punching, wing forming and threading, a nylon or metallic sheet is inserted in the insert groove and fixedly riveted to produce a wing nut able to prevent loosening under a low or high temperature.

Abstract: A manufacturing process of a clinch nut consists in forming a recess zone in a rough casting by cold heading so as to obtain a rough part. The rough part then undergoes a thermal annealing treatment followed by a cold heading operation enabling a bore to be formed designed to contain an internal thread. The internal thread is preferably achieved by tapping by upsetting material from the bore of the nut.

Abstract: A one-piece flag nut having a flag portion protruding perpendicularly to the axis of a nut portion thereof such that during installation, as the flag nut rotates, the flag portion catches on any nearby structure and acts as a wrench during the installation process. The one-piece flag nut is formed by an extrusion process, and preferably formed to have ribs provided on the flag portion thereof which provide strength to the flag nut. The outer edges of the flag portion are preferably rolled to prevent the flag portion from being hung up on the structure during the installation process, thus preventing the flag nut from being properly seated.

Abstract: A method of forming a female fastener including rolling a body portion strip having a midportion and flange portions on opposed sides of the midportion, piercing spaced openings through the midportion, cutting the strip to length between the openings, cold forming a separate generally cylindrical pilot portion having a length greater than the width of the midportion and a diameter greater than the opening through the midportion, preferably including radial splines, and press fitting the pilot portion through the opening in the midportion. The self-attaching female fastener thus includes a rectangular body portion and a generally cylindrical pilot portion having an end face spaced above a plane of the midportion and may be formed of a harder metal than the body portion.

Abstract: The present invention provides for fastener inserts and methods of manufacturing the same. The fastener inserts include selectively removable tangs which can be broken away more cleanly than with other commercially available fastener inserts. Further, the methods of manufacture offer a significant improvement in the production process.

Abstract: A forging method which enables formation of a hollow part by simple processes. In a cutting process, a cylinder blank 1 is cut at the upsetting ratio of L/D=1.5-2.0. In a first process, the cylinder blank 1 is upset in accordance with the outer shape of a nut. The height h of a semi-manufactured product 2 should be lower than the height h of a final product 4. In a second process, dents 3a and 3b are formed on both sides by extrusion. The depth of the dents 3a should be deeper than the other. The height of the semi-manufactured product 3 in the second process should be as tall as the height of the final product 4. In a third process, piercing is performed to the bottom portion of the deeper dent 3a so that both dents 3a and 3b can communicate.

Abstract: A grooved nut including a cylindrical shaft portion having a screw hole at the center, a head portion whose outer periphery is polygonal and which is provided at one end portion of the shaft portion, and a peripheral groove provided at a boundary part between the head portion and the shaft portion, in which the peripheral groove is formed by a plasticizing process.

Abstract: A ball screw 2 or a sliding screw 2a has a driving force-transmitting shaft 4 or 4a and a bearing member 6 or 6a externally fitted to the driving force-transmitting shaft 4 or 4a. The driving force-transmitting shaft 4 or 4a is made of aluminum or aluminum alloy, and the bearing member 6 or 6a is made of any one of synthetic resin, aluminum, and aluminum alloy. The member, which is formed by using the aluminum or the aluminum alloy, is applied with a surface treatment, and preferably, it is further applied with a surface finish treatment.

Abstract: A three-sided, progressively-formed threaded fastener is comprised of a plurality of planar longitudinal faces intersecting at comer areas. Shank tabs extend downward from the bottom of each of the faces at the base of the fastener. Threaded regions along the inside surface of the planar faces are coined indentations applied during the formation of the fastener. A plurality of wedge-shaped protrusions extend downward from the comer areas at the base of the fastener. The combination of shank tabs and wedge-shaped protrusions form a clinch profile along the bottom of the fastener so that it may can be affixed to a sheet of metal by clinch fit.

Abstract: A nut consists of integral metal material and has a female screw threading; screw thread formed with a rolled tap in a screw hole that opens substantially perpendicularly to an end surface of one end of the nu. A concave lead-in is located at an opening end of the screw hole and has a shape including a concave curved portion and a linear tapered portion that are continuous with each other, and extend along the overall periphery of the opening end of the hole. Due to the special concave lead-in, the first thread formed by the rolled tap adjacent to the concave lead-in will not have a concave groove along its crest, although subsequent threads have such a concave groove along the thread crest as a characteristic of thread formation with the rolled tap. Such a thread structure avoids cross-threading when a bolt is engaged in the nut.

Abstract: A fastener for connecting a first panel to a second panel comprises a head and a shaft, the shaft including a plurality of spring legs, each connected at one end to the head and flexing inward and outward relative to the one end. The shaft is dimensioned for insertion into an aperture of the second panel with interference against aperture-defining edges. A plurality of grooves are formed within each spring leg, each groove separated from an adjacent groove by a rib. The rib is configured having a ramped leading surface, a stepped trailing surface and a peak surface disposed between the leading and trailing surfaces. The grooves of one spring leg are axially misaligned with the corresponding grooves of an adjacent spring leg such that each spring leg alternately locks its grooves to the aperture-defining edges of the second panel as the shaft is inserted into the aperture. The head of the fastener can be modified to connect with the first panel in multitude of alternative configurations.

Abstract: A ball rolling groove 1c is defined in an inner peripheral surface of A ball screwed nut 1 by a rolling process, not by a grinding process so that a ball screwed nut having small diameters or large leads can be manufactured. The surface of the ball rolling groove 1c is finished to be sharp without concave and convex by a plastic working by the rolling process, so that the surface is less rough. By rolling the surface by the rolling process excellent in durability, the precision of R shape of the ball rolling groove 1c can be made excellent.