Abstract: A device for fastening equipment parts such as photovoltaic panels on a sandwich or single-shell building envelope using a plurality of fastening elements (20, 20?) in the form of bolts, which can be supported at least by a connection part (30, 30?) and on a load-bearing part (12) of the building or the building envelope. If an outer shell (14) is present, the fastening elements (20, 20?) can be guided through the outer shell (14) and supported on the load-bearing part (12) and/or the outer shell (14). Each fastening element (20, 20?) can be positively engaged with the connection part (30, 30?) and/or, if present, with the outer shell (14) so as in each case to support the connection part (30, 30?) on the load-bearing part (12) and, if present, on the outer shell (14).

Abstract: A fastening element, which may be in the form of a blind rivet or screw, is intended to be fired into an unperforated workpiece. In its front region that is intended to be fired into the workpiece, it includes a punching section which is formed in a cylindrical manner, and has a front end face which extends obliquely to the longitudinal axis. The punching section may be smaller in diameter than the body of the fastening element or else have the same diameter. The section between the end face and the outer side of the punching section forms a punching edge. On account of the oblique profile of the end face, said punching edge is arranged such that, when the fastening element is fired in, the punching edge first of all strikes the metal sheet at one or else at two points, and the opening in the metal sheet is enlarged by shearing off the metal sheet at a point migrating around the circumference.

Abstract: A fastening element, which may be in the form of a blind rivet or screw, is intended to be driven into an unperforated workpiece. In its front region that is intended to be driven into the workpiece, it includes a punching section which is formed in a cylindrical manner and has a front end face which extends obliquely to the longitudinal axis. The punching section may be smaller in diameter than the body of the fastening element or else have the same diameter. The section between the end face and the outer side of the punching section forms a circumferential edge. On account of the oblique profile of the end face, this circumferential edge is arranged such that when the fastening element is driven in, the circumferential edge first of all strikes the metal sheet at a front point. At this front point, the circumferential edge is in the form of a cutting edge extending in the circumferential direction.

Abstract: A self-tapping insert is installed in a pre-existing bore hole in a workpiece by rotating the insert, causing cutting threads on the exterior of the self-tapping insert to cut new threads. Engagement threads on the exterior of the self-tapping insert engage the new threads to retain the self-tapping insert within the workpiece. The self-tapping insert may comprise internal threads which are used to replace damaged threads in the workpiece. The means of installing the self-tapping insert may include a drive bolt having threads which make up into those of the self-tapping insert's internal threads. The self-tapping insert is aligned within the bore hole by means of a detachable pilot, which is connected to the insert with attachment means. The attachment means include the pilot being attached to the drive bolt. The pilot may be attached to the drive bolt means of left-handed threads in an axially-centered aperture of the pilot and matching left-handed threads on the end of the drive bolt.

Abstract: A fastener has a shaft, a head at a first end of the shaft, and a point at the other end of the shaft. A first portion of the shaft adjacent the point is threaded. The first portion typically extends about one-half the total length of the shaft. A second portion of the shaft (adjacent the head) is not threaded, but has a plurality of spaced rings. A knurled portion can be provided between the first and second portions, if desired. Conventional symmetrical or asymmetrical thread can be used in the threaded portion, or a three lobe thread can be used.

Abstract: A concrete screw includes a rod body which has a top end forming a head for tightening operation and a bottom end forming an engaging section. A first thread is formed on the rod body and extends, at a helix angle between 16 and 23 degrees, from the head toward the engaging section. The first thread has a top-side flank that defines a first thread flank angle ranging from 90 to 120 degrees with respect to the rod body. The first thread has a pitch that ranges from 5 mm to 20 mm. Three cutting notches are formed in and distributed along the first thread and are close to the engaging section. The cutting notches have a depth substantially corresponding to a distance from an apex of the first thread to the rod body. The rod body may selectively form a second thread extending between the head and the engaging section.

Abstract: A fastener including a head defining a hexalobular drive hole, a shaft, threads and a pointed end. The hexalobular drive hole can include points having an outermost portion, and the head can include an outer surface, where a thickness of about 0.01 inches to about 0.04 inches is defined between the outer surface and each respective point. The outer surface can be cylindrical, and can transition to a tapered portion that is joined with the shaft. The tapered portion can be frustoconical, angled and/or curvilinear. A related method of installation is provided for advancing the fastener into the side of a first board at an angle to fasten the first board to an underlying second board.

Abstract: A self-tapping screw includes a screw shaft extended downward from a screw head, plural flights of constant-height external thread respectively having the same flight height formed at a part of the screw shaft extended right below the screw head, and plural flights of low-height external thread having flight height decreased gradually toward an end face of a shaft tip portion formed continuously with the constant-height external thread at the shaft tip portion of the screw shaft. A slight arc face is formed continuously at respective connecting parts of upper and lower flanks with upper and lower root faces of the low-height external thread, and the slight arc face is formed so as to extend at least along a connecting part of a lower flank and a lower root face of a constant-height external thread end flight continuing to the low-height external thread.

Abstract: A screw includes a shank and a thread extending spirally around an outer circumference of the shank. The thread includes a plurality of thread convolutions each having a front flank facing an insertion end of the shank and a rear flank facing away from the insertion end. The screw further includes at least one helical groove. The helical groove is formed in the outer circumference of the shank and extends helically along bottom edges of one the front and rear flanks of the thread convolutions. The helical groove is adapted for receiving chippings produced by the thread screwing into articles to be fastened, allowing rapid insertion of the screw into the articles while providing a high tightening force.

Abstract: A screw includes a screw head and a shank connected to the bottom of the screw head. The screw head has a cavity on the top to be wrenched by a screwdriver. The shank is formed in a cylindrical shape and has a point at a distal end, a triangular thread portion helically formed thereon and extended upwards from the point and a circular thread portion extended contiguously upwards from the triangular thread portion. The triangular thread portion has a plurality of thread cusps formed annularly at different angles. The triangular thread portion and circular thread portion have asymmetrical threads. The triangular thread portion has serrated cutting edges on the circumference. Thus the screw can be screwed into a work piece with less friction force and fastened faster and firmer with less effort.

Abstract: A screw has a screw head and a shank. The screw head has a square cavity, a hexagonal cavity or a hexagonal boss to be wedged by a screw driver for wrenching. The shank has a first asymmetrical thread at the taper to facilitate drilling holes, asymmetrical saw-type threads behind the first asymmetrical thread, and a second asymmetrical thread behind the asymmetrical saw-type threads. The shank further has a carved V-shaped tail between the first asymmetrical thread and the asymmetrical saw-type threads to facilitate cutting and debris dispelling. The screw thus formed can rapidly perform thread tapping and debris dispelling, and reduce friction and expand drilling holes and achieve fast fastening.

Abstract: A hole-forming and thread-forming screw for screwing into a sheet piece, including a slotted screw head for accommodating a tool, a threaded shank and a tapering hole-forming part having outer sides with a continuous convex-shaped curve along an entire length thereof, ribs running like threads along the hole-forming part being provided. The hole-forming part ends in a rounded, blunt end piece, and the rounded ribs, which chiplessly displace the material of the sheet part, are situated symmetrically opposite one another and have a pitch that is a multiple of the thread pitch.

Abstract: A versatile fastener including at least two flat areas formed on a cutting part, and an accommodating area disposed between any two of the flat areas. At least two cutting faces are convergent to form the accommodating area, and first and second cutting edges are respectively formed at a connection between each cutting face and flat area. In operation, the flat areas facilitate the first and the second cutting edges to promote a stable balance with the object, thereby allowing the debris to be swiftly guided out of the accommodating areas. Consequently, it is difficult to crack the object while imparting forces thereon, so as to lower the screwing resistance and the fastening torque as well as increase the combining efficiency.

Abstract: A fastening device includes a head and a shank. The shank has opposite ends, one end of the shank is connected to the head, and the other end of the shank defines an operating part. The operating part is capable of cooperating with a disassembling tool to enable the fastening device to rotate with respect to the longitudinal axis of the shank.

Abstract: In the case of a screw having at least one thread (26) that is formed by a rolling process, especially a flat-die rolling process, whereby the thread (26) consists of two ridges of material (28a, 28b) which are shaped from a blank (12) by means of cold-forming during the rolling process in such a way that the thread has a closing crease (32) where the ridges of material (28a, 28b) meet each other, it is provided that the closing crease (32) is situated in the area of a flank (30a, 30b) of the thread (26).

Abstract: A chiplessly thread-forming screw has a stem (11) at one end of which a tip (13) is provided and at another end of which a head (14) is provided, and which has a pointed conical section (21) extending from the tip (13) in a direction of the head (14), a cylindrical section (25) arranged between the first pointed section (21) and the head (14), a first cambered section (22) adjoining the pointed conical section (21) in the direction of the head, and a second cambered section (24) arranged between the first cambered section (22) and the cylindrical section (25) and an outer surface (16) of which has a second curvature radius (R2) unequal to the first curvature radius (R1) of the outer surface (12) of the first cambered section (21).

Abstract: An anti-cross threading screw (1) includes a first threaded portion (4) including a first thread (5) having a first outer diameter (6) and a first pitch (9) and a second threaded portion (12) having a second thread (13) having second outer diameter (18) and a second pitch (21). The second threaded portion (12) is designed as an anti-cross threading portion. The second thread (13) has enlarged an thread crest (15). The second outer diameter (18) of the second thread (13) is smaller than the first diameter (6) of the first thread (5). The first pitch (9) of the first thread (5) is different than the second pitch (21) of the second thread (13).

Abstract: Disclosed is a screw for hard wood, comprising a screw tip (3) with two cutting edges (5) that extend approximately parallel to each other and perpendicular to the longitudinal axis of the screw. The cutting angle of the cutting edges amounts to about 90°. A centering tip (7) which slightly protrudes from the two cutting edges (5) is embodied in the extension of the longitudinal axis of the screw. Said centering tip (7) prevents the screw from deviating to the side at the beginning of the drilling process.

Abstract: A screw (11) includes at least one thread (21) arranged on the screw shaft (12); circumferentially surrounding the shaft (12) at least in some regions, and having a thread pilot (22) located in the free region (15) of the shaft (12) and a plurality of recesses (31) provided in the thread (21) and opening radially outwardly, with the recesses (31) each having a first limiting wall (32) adjacent to the thread pilot (22) and a second limiting wall (33) remote from the thread pilot (22), and a plurality of cutting bodies (26) formed of a material having a hardness greater than a hardness of the thread, located in the recesses (31) formed in the thread (21) and having each a longitudinal axis (27) and an outer surface (28) surrounding the axis (27) at a distance therefrom, with the recesses (31) each having a bearing section (34) with a plurality of generatrices extending substantially along a course of the thread (21) for receiving, at least in some regions, the outer surface (28) of a respective cutting body (26

Abstract: A screw (11) has a shaft (12), a thread (13) which is arranged in at least some areas over the circumference of the shaft (12) and which defines a helix (14), and cutting bodies (26; 36; 46; 56, 66) made of a material having hardness greater than the hardness of the thread (13) and arranged in recesses (20, 21) of the thread (13), with the cutting bodies (26; 36; 46; 56, 66) having their longitudinal extension oriented along the helix (14) so that their longitudinal axes (27; 37; 47; 57, 67) enclose an angle (A; B; C; D, E) of ?35° to +35° with the respective tangents of the helix (14).

Abstract: A fastening method of a fastener, applied to combine a metal object with a target object, prepares a holder, a cover, and a screw penetrating through the holder in a preparing step, drills a pre-drilled hole on the metal object to receive the holder and to secure the screw in a prearranging step, fixes the screw cased with the holder to the target object in a securing step, and finally places the cover on the holder for enveloping a head of the screw in a lodging step. Accordingly, the screw cased with the holder prevents a shank of the screw from having a direct contact with the metal object. Thus, the screw is not subject to rustiness.

Abstract: Screw connection for a fixed connection of two assemblies which are mounted to each other in a variable position, using a connecting member penetrated by a screw. The connecting member is mounted between the assemblies by means of a self-cutting screw penetrating the connecting member and one of the assemblies, which screw is grooving its thread into both parts in such a way that, starting from a stable end position of the one assembly and the connecting member, the screw is adapted to be screwed into the connecting member as well as into the one assembly by means of thread grooves such that, by means of the self-cutting thread of the screw, the connecting member and the one assembly are held in a fixed position with respect to each other, and the other assembly is fastened directly to the connecting member.

Abstract: A sprocket cover arrangement for a hand-held chain saw has a housing and a sprocket cover that has an opening and is connected to the housing. At least one stud bolt having a first end secured to the housing and having a second end that is a free threaded end is provided. The free threaded end projects through the opening of the sprocket cover to an exterior side of the sprocket cover when the sprocket cover is positioned in an operating position on the housing. A nut is screwed onto the free threaded end of the at least one stud bolt on the exterior side of the sprocket cover so as to secure the sprocket cover on the housing. The nut is secured captively, rotatably and with play in the opening of the sprocket cover.

Abstract: A screw which can be manufactured at a low cost with a relatively simple constitution by performing precise machining suitable for tightening a screw without employing a tapping thread structure as a threaded portion shape and machining only the distal end of the threaded portion to have a shape projecting spherically, and which can ensure smooth and quick screw tightening work without causing such problems as heat generation or molding powder at all at screw tightening. The screw includes a head (12) provided with a bit fitting groove (13) at one end, and a threaded portion (14) which is machined precisely with substantially equal circular diameter over a full length, wherein the distal end (20) of the threaded portion (14) is shaped to have a spherical projection varying in a plurality of stages.

Abstract: An asymmetric thread impact drivable screw and clip for use with a power impact device for penetrating wood fibers while minimizing cut fibers. The screw includes an impact head and a conical shaped tip having a ballistic insertion angle at the ends of a shank. The shank defines asymmetrical threads with an insertion flank having a long side at a slide angle peaking at a crest supported by a catch flank positioned at a grip angle. Varying tool accepting recess are taught for the head along with multiple thread sections. A mushroom compaction thread section is also taught.

Abstract: A screw with a polygonal cross section comprises a threaded section and a non-threaded section that extends from the threaded section to a front, rounded screw tip. The sideline of the non-threaded section runs smoothly and without interruption from the threaded section to the tip at a constant curvature. The screw is used to attach an element to a panel component, wherein the screw itself produces the hole in the panel component and forms the threads.

Abstract: A thread-furrowing screw comprises a shaft portion made of solid material and a thread portion attached to the shaft portion, which thread portion is wound from a profiled metal strip.

Abstract: A wall anchor system includes an anchor member installable into a hollow wall. The anchor member includes a body having a first end that extends to a second end through an intermediate portion. The body includes an internal passage having a fastener retaining feature provided adjacent the first end. A fastener member is operatively engageable with the anchor member.

Abstract: A fastener for composite material having a dense composition employs a head which has a socket and a recessed underside and a lower rim. The shank has an upper portion with an enlarged diameter and a left hand thread while the lower portion has a tri-lobed configuration and is traversed by a right hand thread. The right hand thread may have a plurality of notches which, in one embodiment, are arranged in a spiral array.

Abstract: An insulated roof deck system which can be used in installing metal roofs is set forth. The system includes a plurality of metal purlins (10), a plurality of metal roof panels (2), a plurality of thermal insulation blocks (4), cleats (14), and threaded fasteners (12). The metal purlins (10) can form a parallel array of purlins. The metal roof panels (2) can be attached to the metal purlins (10) in the parallel array. The thermal insulation blocks (4) can be disposed between the metal purlin (10) and the metal roof panel (2). The cleat (14) can be disposed between the thermal insulation blocks (4) and the metal roof panel (2) and has a protrusion which is capable of securing the thermal insulation block (4) and inhibits lateral movement between the thermal insulation block (4) and the cleat (14). The threaded fastener (12) secures the metal roof panel (2), the cleat (14), and the thermal insulation block (4) to the metal purlin (10).

Abstract: A screw for the creation of a metric thread in a female element, includes a load-bearing (metric) thread portion and a forming thread portion which is tapered to the tip of the screw. The flights of the tapered thread portion are sharp-edged and fully formed.

Abstract: A fastener element (16) has a head section (18), a threaded shank section (17) with threads (20) at a pitch and a distal end section (22). A retention device (24) is secured to the distal end section and is engageable with a fastener receiving member (14).

Abstract: A screw has a screw head and a shank. The screw head has a square cavity, a hexagonal cavity or a hexagonal boss to be wedged by a screw driver for wrenching. The shank has four sections of threads on the periphery. A first thread is asymmetrical to facilitate drilling holes and spaced with a first threaded pitch. A second thread has a carved V-shaped tail end extended in a direction of the shank at a length larger than one of the first threaded. A third thread has asymmetrical saw-type threads, and a fourth tread is asymmetrical. The screw thus formed can rapidly perform thread tapping and debris dispelling, and reduce friction and expand drilling holes and achieve fast fastening.

Abstract: The present invention provides a tightening structure with which a reduction in processing steps is achieved without modifying the shape of a partner member an improvements in bolt strength and fatigue strength are achieved, and with which the fitting length of a thread ridge is not altered greatly in comparison with a conventional tightening structure such that a size reduction can be achieved, thereby contributing greatly to a reduction in the weight of a vehicle.

Abstract: The present invention pertains to a screw with a first thread section comprised of a trailing and a leading thread segments respectively spiraled on a shank and a tip section. Distinctly, the leading thread segment defines a plane surface thereon to convergently engage with an adjacently thread peak on the trailing thread segment and further constructs a thread width greater than that of the trailing thread segment while aligning the two thread segments with a correspondent profile thread height. Such configuration of the plane surface accompanies its larger thread width to enlarge a drilling channel and accordingly renders an easy entry of the trailing thread segment into an object with less friction and higher screwing speed. Additionally, the debris is partially removed through the void between the enlarged channel and the trailing thread segment to avoid cracking the object, decrease drilling torque, and enhance the fastening capability.

Abstract: In a bolt of the present invention, a guide portion having a small diameter is formed at the distal end of a shaft portion and ridge having an inverted direction screw configuration relative to the ridge formed on a constant diameter portion is formed. When the bolt is inserted obliquely into a nut and the ridge gets into engagement with a female screw portion of the nut, an effect of floating the bolt is generated, and the bolt cannot be driven into the nut unless it is set in an appropriate tightening posture. Consequently, biting and seizing of the bolt to the nut can be prevented securely. If the ridge is formed into a double threaded screw having an inverted direction screw configuration, the effect can be further intensified.

Abstract: A self-tapping insert is installed in a pre-existing bore hole in a workpiece by rotating the insert, causing cutting threads on the exterior of the self-tapping insert to cut new threads. Engagement threads on the exterior of the self-tapping insert engage the new threads to retain the self-tapping insert within the workpiece. The self-tapping insert may comprise internal threads which are used to replaced damaged threads in the workpiece. The exterior threads of the self-tapping insert may be configured as left-handed threads, while the internal threads are right-handed threads. The top of the self-tapping insert may comprise a plurality of castellations, and a drive head having matching castellations may be employed to install the self-tapping insert, eliminating the need for installing the insert with a drive bolt. The exterior of the self-tapping insert may further comprise a leading edge for cutting the new threads, where the leading edge has greater radial extension than the trailing edge.

Abstract: A screw with wave thread including a head, a shank extending therefrom, and a thread spirally disposed on the shank; in particular, the thread has respective first and second threaded sections. Each thread unit of the second threaded section defines a continuous wave-shaped directrix around the shank for a base. A plurality of thread segments are formed on each thread unit of the second threaded section, and each of which has an upper flank as well as a lower flank extended from the shank and disposed along the wave shape directrix to form into a wavy arrangement around shank, thereby disposing more peaks converged by the upper flank and the lower flank for increasing the drilling capability.

Abstract: The invention relates to a screw (1) having a threaded shank (2) and a screw tip (6). The threaded shank (2) is composed of a shank core (10) and a thread which extends helically over the shank core (10). Two flanks (15, 16) which converge in an outer thread edge (14) has a height (H) measured radially from the shank core (10) to the thread edge (14). The thread (12) has a specific apex angle (?) formed between the adjacent flanks (15, 16). Preferably the outer thread edge (14) extends in a wave form in the radial direction with an amplitude (U) between wave crests (20) forming indentations (24) which interrupt the surface of the flank (15/16). At least one of the two flanks (15, 16) of the thread (12) is formed concavely in the region between the shank core (10) and the thread edge (14), seen in radial profile, in such a way that the apex angle (?) is less than a flank angle (?F). With preference, the thread (12) respectively has in the regions that are not interrupted by indentations (24).

Abstract: It is possible to prevent a screwing torque from becoming excessively high even when a screw is threadedly engaged into a deep guide hole. In a tapping screw 100 comprising a parallel screw 22, a taper thread 23 provided closer to a tip end of the tapping screw than the parallel screw 22, and a plurality of projections 30 which partially project along an apex and flanks on both sides of a screw thread and which form an internal thread on a surface of a guide hole formed in a to-be fastened member, the plurality of projections 30 are provided from a region where the taper thread 23 is provided to a portion of a region where the parallel screw 22 is provided, and a diameter of a virtual cylinder which comes into contact with tip ends of some of the projections 30 including a projection provided in a region where the parallel screw 22 is provided is larger than an outer diameter of a external thread of the parallel screw 22.

Abstract: The object of the present invention is to provide a bolt that effectively prevents gouging, seizure and racing between the bolt and nut without the aid of a guide boss and is effective when combined with the case nut. The object can be attained by providing a bolt having a threaded shank portion wherein a plural number of notched faces slanting toward the end of the threaded shank portion at an angle ranging from ±15° to ±80° toward the axis of the threaded shank portion, are formed at the beginning of the thread part of the threaded shank portion.

Abstract: A thread-tapping screw (11) has a thread (21) extending, starting from the screw shaft free end (15), at least along a portion of the shaft length and a height of which constantly decreasing toward the free end (15) of the shaft (12), and a plurality of cutting bodies (26, 36, 46, 56, 66) formed of a material having a greater hardness than hardness of the thread (21), located in recesses (24) formed in the thread (21) and opening radially outwardly and having, respectively, a radial outer profile (27, 37, 47, 57, 67) projecting, at least partially, beyond the thread and a height (A, B, C, D, E) of which decreases toward the free end (15) of the shaft (12) stepwise.

Abstract: A connecting bolt has: a screw rod which has threads in outer circumference part; a guidepost which is integrally formed so that the guidepost projects from a tip part of the screw rod, and which is the same outer diameter size as the root diameter of a thread, or is outer diameter size smaller than the root diameter of a thread; a shavings insertion hole which is formed in the guidepost and the screw rod; a tap part which is formed in a thread near the guidepost; a notch which is provided at least two or more, guides shavings into the shavings insertion hole, and is formed in the tap part and the guidepost; and a connecting means of the shape of a bolt or a nut which is integrally formed in the back end part of the screw rod. And the connecting bolt can attach to the pillar and the beam of a timber material easily, and the fixed state at the time of attachment is not visible from outside, and makes appearance beautiful.

Abstract: The present invention pertains to a screw for use in nonmetal objects comprising a plurality of cut-aiding portions formed by the longer and shorter cutting surfaces inclined toward opposite directions. Further, a cutting edge formed by the junction of any two adjacent cutting surfaces presents in a fastening direction of the screw. Thus, the cutting edge assists the threads to thoroughly severe and to shatter the fibers and debris of the objects, which can also be accommodated into the cut-aiding portions. Also, the ridge of the longer cutting surface aids in cutting fibers and further guides the debris out. In this manner, the present invention facilitates to enhance cutting capability for obtaining less screwing resistance, to prevent the destruction of the object and to increase the screwing speed.

Abstract: An anti-cross threading screw (1) includes a first threaded portion (4) including a first thread (5) having a first outer diameter (6) and a first pitch (9) and a second threaded portion (12) having a second thread (13) having second outer diameter (18) and a second pitch (21). The second threaded portion (12) is designed as an anti-cross threading portion. The second thread (13) has enlarged an thread crest (15). The second outer diameter (18) of the second thread (13) is smaller than the first diameter (6) of the first thread (5). The first pitch (9) of the first thread (5) is different than the second pitch (21) of the second thread (13).

Abstract: The invention relates to a self-boring and thread-forming tapping screw having a screw shaft with a screw tip at one end and at the other end a force application member for the transmission of a turning moment. The screw shaft includes a threaded section with the screw tip and an adjacent thread-free section of the shaft including the force application member. The threaded section has a shaft core and a self-tapping thread. The threaded section includes a core section axially displaced from the tip and having a polygonal core cross section. Corners of the core cross section define an enveloping circle with an enveloping circle diameter larger than a shaft diameter of the thread-free section.

Abstract: The object of the present invention is to provide a bolt that effectively prevents gouging, seizure and racing between the bolt and nut without the aid of a guide boss and is effective when combined with the case nut. The object can be attained by providing a bolt having a threaded shank portion wherein a plural number of notched faces slanting toward the end of the threaded shank portion at an angle ranging from ±15° to ±80° toward the axis of the threaded shank portion, are formed at the beginning of the thread part of the threaded shank portion.

Abstract: A screw which can be manufactured at a low cost with a relatively simple constitution by performing precise machining suitable for tightening a screw without employing a tapping thread structure as a threaded portion shape and machining only the distal end of the threaded portion to have a shape projecting spherically, and which can ensure smooth and quick screw tightening work without causing such problems as heat generation or molding powder at all at screw tightening. The screw includes a head (12) provided with a bit fitting groove (13) at one end, and a threaded portion (14) which is machined precisely with substantially equal circular diameter over a full length, wherein the distal end (20) of the threaded portion (14) is shaped to have a spherical projection varying in a plurality of stages.

Abstract: A threaded element of plastic material for a joining assembly has a uniquely formed thread profile of a small profile angle between 30° and 50° and a rounded crest of a relatively large radius of curvature. The gap between the revolutions of the thread is of a volume which exceeds that of the thread. In order to provide for a specific cutting geometry of the thread profile the threaded element comprises a plurality of angular segments which are radially offset with respect to each other such that adjacent angular segments provide cutting edges. Furthermore, a tool and a method for making such a joining assembly are disclosed.

Abstract: A thrust screw (14) for applying force against an object. The thrust screw (14) comprising a housing having a ball (12) secured therein. The ball (12) having a flat planar surface (16) which contacts the objects for applying force against the object.