Abstract: A wood screw structure comprises a screw head section, a rod section, a first screw thread and a plurality of crushing rib units. The rod section is sequentially integrally formed from the screw head section and comprises a first rod portion connecting the screw head section, a second rod portion, a third rod portion, and a tapered portion extending and tapering outwardly from the third rod portion. The first screw thread is disposed spirally and is protruded on an outer peripheral surface of the tapered portion, the second rod portion and the third rod portion. The crushing rib units are disposed spirally and protruded around the outer peripheral surface of the third rod portion and the tapered portion, and each of the crushing rib units includes a plurality of crushers protrudingly disposed on a rib body. A first discharge gap is formed between the crushers.

Abstract: A fastener for assembling at least two structural elements having an aperture, may have a fastener comprising an enlarged head (12) and a shank (14) exhibiting, prior to fitting, an outside diameter (D1) greater than an inside diameter (DS) of the aperture, and a locking portion comprising a screw thread or annular grooves. The fastener further comprises a lubricating sacrificial ring (40) on the exterior surface of the fastener, extending at least between a distal end of the shank and a proximal end of the locking portion, said ring having, before the fastener is fitted into the structure, an outside diameter greater than a diameter of the aperture. The sacrificial ring comprises a polymer resin forming a matrix encapsulating dispersant molecules and oil molecules. The fastener assembly may apply to the assembly of aircraft structures.

Abstract: The present disclosure provides a threaded fastener having a hybrid self-drilling tip or drill tip. The fastener includes a head, a shank connected to and extending from the head, a helical thread formation extending radially outwardly from part of the shank, and a self-drilling tip including a first tapered tip portion and a second tapered tip portion. The first tapered tip portion is connected at a first end to the shank and at a second end to the second tapered tip portion, and the second tapered tip portion terminates in a pointed end. The outer diameters of both tapered portions taper radially inwardly moving in the direction of the pointed end, which renders the fastener suitable for attachment to wood as well as for fastening two metal objects to one another.

Abstract: A sheet metal screw includes one or more of a tapered self-drilling tip, an asymmetric thread angle and/or a trilobular thread edge profile.

Abstract: An orthopedic fastener having compound parabolic petals configured to secure within trabecular bone during orthopedic procedures by compressing the trabecular bone while minimizing the lacerating effect of traditional screws and correspondingly reducing trauma to the trabecular bone. The compound parabolic petals are configured to progressively compress the trabecular bone during advancement of the orthopedic fastener through the trabecular bone in a compress-partial release-compress progression along a shaft of the orthopedic fastener and create a secure connection thereto with compression distributed along the length of the orthopedic fastener, and center a proximal end of the shaft/orthopedic fastener within an insertion point of the orthopedic fastener.

Abstract: A self-drilling, self-tapping bone screw is described in which the bone screw has a drill tip free of threads and having a length at least as great as about the thickness of a proximal cortical bone layer, with the drill tip having opposed lands and a helical flute between each of the lands with each of the lands having a cutting edge configured to cut bone as the drill tip is rotated into the bone with the flutes conveying the bone debris away from the drill tip, where a lead thread begins to self-tap internal threads in the proximal cortical bone layer after the drill tip has drilled through the proximal cortical bone layer so as to avoid stripping the threads formed in the bone layer. A method of installation is also disclosed.

Abstract: A screw anchor for a trussed foundation system to support single-axis trackers and other structures and related methods of driving such a screw anchor into underlying ground. A hollowed tube of uniform diameter is open at both ends with a thread form beginning at one end and circumscribing a portion the tube, the thread form having a tapered lead-in. The open-ended geometry allows a mandrel or rock drill to be inserted and operated through the anchor during driving to expedite the driving process. The tapered thread form provides a lead-in for driving the anchor into a rock bore.

Abstract: A screw has a shaft section which extends axially, a screw thread at the shaft section, which screw thread has thread turns that extend radially starting from the shaft section, a screw tip section which connects to the shaft section, at least one first scraping edge at the screw tip section, and at least one second scraping edge in a region of the shaft section adjacent to the screw tip section. The at least one first scraping edge and the at least one second scraping edge are spaced at a distance from each other and extend in an axial direction over different areas of the screw.

Abstract: A screw for securing dense wood material has a head with a specially configured drive socket and an underside with an array of lobes. The lobes preferably have a left-handed orientation and have chamfered extremities. The shank is specially configured with an upper thread, an intermediate unthreaded portion and a lower thread which terminates with a half-point tip. In one embodiment, the upper thread major diameter is slightly smaller than the major diameter of the lower thread. The upper thread has a greater thread density than the lower thread. The upper to lower thread-per-inch density is preferably in the range of 1.3:1 to 1.7:1. The screw is specifically configured to assist in applications where there are wet fibers near the wood deck surface.

Abstract: The present disclosure describes a coated implant for bone repair that is biodegradable. The coated implant includes an implant body formed from a magnesium alloy, and a porous ceramic coating disposed on at least a portion of an outer surface of the implant body. The porous ceramic coating can include MgO, Mg(OH)2, Mg3(PO4)2, and oxides of alloying elements of magnesium.

Abstract: A crack-proof screw comprises a head; a rod having a first end extending from the head and having a rod thread near the head and expanding threads far away from the head; each expanding thread encircled through an angle smaller than 360 degrees; the screwing direction of the expanding thread being identical to or different from that of the rod thread; a tapered tail extending from a second end of the head; the expanding threads on the rod being near the tapered tail; the tapered tail having two drilling threads; each drilling thread can be extended to or not extended to the tip end of the tapered tail.

Abstract: A plug (1) for sealing a hole (2) provided in a work piece (3). The plug (1) comprises a front part (4) and a sealing part (5), and the surface hardness of at least the sealing part is greater than the hardness of the work piece (3). The sealing part (5) is conical and has an increasing diameter, in a direction from the front part (4) and the sealing part (5) comprises a cutting thread (6). The profile of the cutting thread (6) comprises a sharp tapered top (7), two adjacent flat flanks (8), and a bottom (9) of the thread (6). The sharp tapered top (7) is formed by the two flanks (8) which meet at a common intersection point. An angle (?, ?) between the flanks (8) is between 110-160° while transitions between the flanks (8) and the bottom (9) are smooth.

Abstract: A pipeline fastener defines at least one hole formed on a hollow shank with a channel formed therein and has a chip-removing section at least formed between the hole and the channel of the shank. A diameter of the chip-removing section is bigger than a bore diameter of the hole. Accordingly, by the chip-removing section with the bigger diameter, burrs which are originally formed at a convergence between a bore surface of the hole and a periphery of the shank can be removed. Consequently, following burr-cleaning procedures are reduced to lower the production cost, and damages of the burrs to other objects at the time of using the pipeline fastener are further prevented, thereby improving the safety of the use efficiently.

Abstract: A fastener including a chisel point that pre-bores a hole in a work piece to prevent damage to the work piece as the fastener advances. The fastener can include a head, a shaft and a chisel brake point formed at an end of the shaft. The chisel brake point can include first and second opposing inclined surfaces disposed at an angle of about 80° to about 150° relative to one another. A thread can begin adjacent the chisel brake point and form an extension of an inclined surface and/or a chisel edge. The chisel brake point can scrape material from a work piece while pre-boring a hole. The material can be transferred to the thread, and subsequently fed up the thread, out of the pre-bored hole. The chisel brake point can also selectively retard advancement of the fastener into the work piece. Methods of installing the fastener also are provided.

Abstract: Fasteners are provided that include a head and having a head, a tip end having a tip, a first body portion having right-hand threads, and a second body portion having left-hand threads. The first body portion is adjacent to the tip end of the fastener and extends a first distance along a length of the fastener towards the head end. The second body portion is adjacent to the first body portion, and extends the head end of the fastener and extending a second distance along the length of the fastener towards the head end. The right-hand threads, and the left-hand threads, can have a thread angle ? of less than about 60°.

Abstract: Fasteners are provided that include a head and having a head, a tip end having a tip, a first body portion having first threads having a pitch angle, and a second body portion having second threads, the second threads having a different pitch than the first threads. The first body portion is adjacent to the tip end of the fastener and extends a first distance along a length of the fastener towards the head end. The second body portion is adjacent to the first body portion, and extends the head end of the fastener and extending a second distance along the length of the fastener towards the head end.

Abstract: A dental implant device for insertion into a bore defined in bone for use with a prosthetic tooth or dental appliance includes an abutment with a plurality of male keys disposed about the distal end of the abutment capable of being affixed to the prosthetic tooth or dental appliance, an implantable anchor having a proximal and distal end, a plurality of female keyways defined into the proximal end of the anchor, the keyways capable of coupling to the male keys of the abutment and thereby preventing relative rotation of the abutment and anchor; an interlocking thread helically defined around a longitudinal axis of the anchor, the thread being adapted to couple to the bore defined in the bone and means for coupling the abutment to the implant anchor.

Abstract: A screw includes a shank, at least one end cutting groove, a first thread, and a second thread. The shank includes a lower section disposed near an insertion end thereof and an upper section disposed near a head end thereof. The lower section has triangular transverse cross sections, and the upper section has circular transverse cross sections. The end cutting groove is formed in the lower section of the shank, and an included angle between 3 and 9 degrees is formed between an extending direction of the end cutting groove and a longitudinal axis of the shank. The first thread is disposed on the lower section of the shank and includes a plurality of asymmetrical thread convolutions.

Abstract: A screw with low drilling resistance comprises a head portion, a shank portion, a plurality of first threads, a drilling portion, and a plurality of second threads. Wherein, a plurality of opening slots are correspondingly defined on the second threads, and a first included angle of the first threads is smaller than a second included angle of the second threads. Thereby, the opening slots on the second threads efficiently provide the first threads with an auxiliary cutting effect and preferably offers a debris accommodating room. The first threads including the smaller first included angle favorably reinforce the bearing force of the second threads including the larger second included angle, thereby promoting the cutting effect of the screw and allowing a speedy screwing.

Abstract: In the case of a thread-tapping screw (1), especially a concrete screw (2), including a screw head (3), a screw shank (5) and a thread (6) that is formed on at least part of the screw shank (5), whereby at least one longitudinal groove (9) is formed on a front section (7) of the screw (1), starting at the end (4) of the screw on the screw shank (5), and the at least one longitudinal groove (9) is delimited on the screw shank (5) by two lengthwise sides (10) running essentially radially relative to a longitudinal axis (8) of the screw (1), it is the objective that the tightening torque needed when the screw (1) is being screwed into a drilled hole should be slight, and that the screw (1) should be produced cost-effectively.

Abstract: A secondary screw that is used to penetrate through a conventional threaded screw. The secondary screw is inserted into a conventional screw that might be mounted or inserted into a wall or a post. The secondary screw provides a means to avoid leaving a hole in a wall or post by removing the primary threaded screw. In one particular embodiment, a primary screw is inserted into a wall, then the secondary screw screws into the top head of the primary screw. This arrangement enables a user to use the secondary screw as a means to hang any object upon the screw or mount any object through the use of the secondary screw.

Abstract: A fastening element for hard constructional components such as concrete, masonry, and the like, includes a cylindrical base body (22; 42; 62) having an inwardly located engagement element (28; 48; 68) for the setting bit and formed as a through-opening (31; 51; 71) in the bottom section (23; 43; 63) which is provided at the first end of the base body, a receptacle (29) opening toward the second end (25), remote from the first end and adjoining the engagement element (28; 48; 68) in a direction toward the second end (25), and provided with load application means (30; 50); and a self-tapping thread (27) provided, at least regionwise, on an outer surface (26) of the base body (22, 42; 62).

Abstract: A thread forming fastener for threading into a nut anchor of a pliable material wherein there is produced during the driving of the fastener a combination of forces that encourages the nut anchor material to flow smoothly and to develop a mating thread in the nut anchor that minimizes stress cracking and radial hoop stress as the mating thread is being formed. The fastener comprises a drive head and a shank extending from the head and having a longitudinal axis, the shank including a core and a thread having a selected axial pitch, a selected thread height and a profile which in axial cross-section includes a leading face, a trailing face and a tip. The leading face is composed of a radially inner concave portion having a first radius and which transitions smoothly to a radially outer convex portion having a second radius, the transition occurring at a point on the common tangent to those portions.

Abstract: Tapping screw (1) has conical portion (4) at the end of cylindrical portion (3) and thread (6) of tapered screw portion (M) disposed at conical portion (4) are formed of single-start threads roughly pitched, wherein the tip angle of conical portion (4) is conically formed at an acute angle of about 30 degrees, and second thread (7) extending in parallel with thread (6) of tapered screw portion (M) is disposed at the end of conical portion (4), forming double-start thread (6, 7) at the end of conical portion (4), and the axial length of tapered screw portion (T) formed of double-start thread (6, 7) is greater than the thickness (upper limit 1.6 mm) of the metal sheet to be fastened.

Abstract: A concrete screw includes a screw head and a rod with a drilling tail section at a distal end thereof. The rod includes a first thread section formed annularly thereon and extended upwards from the drilling tail section, and a second thread section encircling between at least two thread pitches of the first thread section and having an outer diameter smaller than that of the first thread section. The rod further includes a third thread section on an upper end thereof encircling between at least two thread pitches of the first thread section. As the outer edge of the second thread section butts the wall of the screw hole, the first thread section can steadily perform cutting without swaying. Moreover, through the third thread section, compact effect is thereby achieved at a position near the screw head. Hence the concrete screw can provide precise, effort-saving and steady fastening effect.

Abstract: A self-tapping fastener, which has been especially constructed for use in connection with the insertion and installation thereof into stucco, gypsum, wallboard, or other hard board substrates, wherein the forward end portion of the shank portion of the self-tapping fastener is provided with a pair of diametrically opposed flat sections which effectively form at least one pair of diametrically opposed tapping threads so as to effectively perform the thread tapping process despite exhibiting some abrasion of the forwardmost threads. In addition, the flat sections also effectively define recessed pockets for accommodating any dust, particles, debris, or the like, which will be generated during the thread tapping process.

Abstract: A building structure including a first building member and a second building member may be connected by fasteners, each fastener having a head, a tapered lead portion having an angle from 30 to 60° of at least HRC 50 hardness adapted to start into a pilot hole, a thread-forming portion of at least HRC 50 hardness adapted to thread the fastener into at least the second steel building member, and a threaded portion having a through hardness from about HRB 70 to HRC 40, such that the fastener is capable of providing a ratio of failure torque to thread-forming torque of at least 3.0 and a ratio of failure torque to drive torque greater than 10 when the second steel building member has a thickness of about 0.25 inch and the pilot hole has at least one diameter within nominal diameter from 80 to 98% of major diameter.

Abstract: A fastening mechanism includes a basic body made from a base metal, onto which at least one corrosion-resistant layer is applied. A further layer is applied at least partially onto the at least one corrosion-resistant layer. The further layer has a lower coefficient of friction than the at least one corrosion-resistant layer.

Abstract: An eye bolt has an elongate threaded shank having a longitudinal axis and a loop projection, such as a circular loop, extending from one end of the shank and a driving head rigidly mounted on the loop projection coaxially with the axis. To facilitate insertion into a material, the shank may include a self drilling and self tapping portion at the opposite end portion of the shank. A rotational driving force applied to the driving head causes the self drilling and self tapping portion to drill a hole in the material into which the threaded portion on the shank is screwed.

Abstract: A screw comprises a head and a rod extended downward from the head. The rod has a tip at a distal end and a round thread spirally extended upward from the tip. The round thread is an asymmetric thread and has serrated cutting edges extended upward from the tip and formed along a circumference in a desired distance. The rod also has a cutting thread with a plurality of spiral cutting edges spirally extended upward from the tip in the same spiral direction as that of the round thread. When the screw is screwed into a workpiece, the asymmetric thread can effectively reduce resistance of screwing. Further, the serrated cutting edges and the cutting thread of the invention can increase the cutting effect. Thereby, the screw of the invention enables the user to fasten workpieces faster with less effort.

Abstract: A drilling screw with compound threads comprises a head at one of the screw; a drilling tip at another thereof; a screwing rod extending from the head to the drilling tip; a middle section of the rod being formed with a flange; at least one tightening thread formed on the rod and between the flange and the head; at least one drilling thread formed on the screwing rod and extended between the flange and the drilling tip; and at least one expanding thread formed on the screwing rod and extended between the flange and the drilling tip. The thread angle of the expanding thread is identical to that of the drilling thread. A height of the expanding thread is smaller than that of the drilling thread and the spiral direction of the expanding thread is opposite to that of the drilling thread. The drilling operation is performed smoothly and firmly.

Abstract: In a self-tapping anchor screw for application in mining, tunnel construction, above-ground or below-ground construction, and for screwing into rock or into a building, comprising a screw shaft, which comprises a frontal end and a rear end, a drill head embodied at the frontal end of the screw shaft, a self-tapping thread to fasten the anchor screw in a bore hole implemented by the drilling head, the anchor screw allows cost-effective production with little technical expense and reliable fastening. The anchor screw comprises a fastening element as a separate component complementing the screw shaft and the self-tapping thread is embodied at the fastening element.

Abstract: A self-counterboring screw-threaded headed fastener, for the threaded insertion into an underlying fixed support or substrate in order to fixedly secure a structural component, such as, for example, an insulated metal panel (IMP), to the underlying fixed support or substrate without the need for pre-drilling a bore within the insulated metal panel (IMP), in order to accommodate the screw-threaded head of the fastener, prior to the insertion of the screw-threaded fastener into and through the insulated metal panel (IMP) for fixation within and to the underlying fixed support or substrate, is disclosed. Cutting wrench or screw-gun sockets are also disclosed for similar purposes.

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: Tapping screw (1) has conical portion (4) at the end of cylindrical portion (3) and thread (6) of tapered screw portion (M) disposed at conical portion (4) are formed of single-start threads roughly pitched, wherein the tip angle of conical portion (4) is conically formed at an acute angle of about 30 degrees, and second thread (7) extending in parallel with thread (6) of tapered screw portion (M) is disposed at the end of conical portion (4), forming double-start thread (6, 7) at the end of conical portion (4), and the axial length of tapered screw portion (T) formed of double-start thread (6, 7) is greater than the thickness (upper limit 1.6 mm) of the metal sheet to be fastened.

Abstract: A building structure including a first building member and a second building member may be connected by a plurality of fasteners, each fastener having a head, a threaded portion having a through hardness of between HRB 70 and HRC 40, a thread-forming portion of at least HRC 50 hardness enabling the fastener to form threads in at least the second steel building member, and a fluted lead portion of at least HRC 50 hardness with a nominal diameter between 70 and 95% of major diameter, such that the fastener is capable of providing a ratio of strip torque to thread-forming torque of at least 3.0 and a ratio of strip torque to drive torque greater than 6.0 when the second steel building member having a thickness of 0.25 inch and the fluted lead portion having at least one diameter within nominal diameter between 80 and 98% of major diameter.

Abstract: A self-tapping screw includes a threaded shank, a drill bit and a head. The drill bit is provided with two blades each provided with at least one cutting slot. Thus, the cutting slot of each of the two blades performs a cutting action during the tapping process to aid the tapping action of the two blades so as to increase the self-tapping velocity of the blades and to shorten the working time of the drill bit. In addition, the cutting slot of each of the two blades can proceed the cutting and tapping action to prevent the drill bit from being inoperative when the two blades are broken or worn out during a long-term utilization so as to enhance the lifetime of the self-tapping screw.

Abstract: A screw, in particular a self-tapping screw, has a screw thread which covers up to the front end of the screw formed as a drilling tip or cutting tip. In the front area, starting with a distance from the front end of the screw, there is an opposite thread showing the same pitch as the screw thread, however, its thread height is lower than the thread height of the screw thread. This second, opposite single-thread, double-thread or triple-thread/multi-thread forms a cutting edge with its thread edge which is used to cut fibers in order to reduce wedge effect during screwing in the screw. The screw is particularly suitable for wood or wood-like materials in the edge areas of structural elements.

Abstract: Disclosed is a method for manufacturing a screw with helical chip discharge channel, including providing a blank, subjecting an end of the blank to form a head and subjecting the blank to rolling to form one or more sections of threads. The screw is formed with one or more helical chip discharge channels, which can be of different helical angle according the different applications. The chip discharge channel can be formed by milling, rolling, or combined rolling and milling. The chip discharge channel is extended into the threads to form tapping edges. As such, the tapping operation is made effortless and the shape of the tapped thread excellent. The extending angle of the chip discharge channel can be changed according to different materials of the workpiece to be fastened. The length of the chip discharge channel can be selected according to different applications.

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 an integral hexagonal shape, and a drive socket of corresponding size and shape may be employed to install the self-tapping insert, eliminating the need for installing the insert with a drive bolt, and permitting the left-handed rotation of the self-tapping inserts external threads.

Abstract: A method is described for anchoring a fastening element (11) in a mineral component (1), in which a bore hole (2) is provided in the component (1) using a drill bit having a nominal drill bit diameter, and a fastening element (11) is then screwed into the provided bore hole (2). The fastening element (11) has a shank (12) which is provided with rotary engagement device (16) for a setting tool, and has a core diameter (K) and cutting edges (21) on a first end region. The fastening element has a self-tapping thread (17) in which the difference between the outer diameter of the thread (17) and the core diameter (K) of the shank (12) corresponds to 0.05 to 0.7 times the pitch of the thread (17). A drill bit is used which has a nominal drill bit diameter corresponding to 0.95 to 1.10 times the core diameter (K) of the shank (12). Also described is a fastening element (11) for anchoring in a mineral component (1).

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: A fastening element having a torque-receiver for a setting tool and having a shank bearing a tapping thread that has a free end facing away from the torque-receiving means, and that has a thread-core diameter. The thread has one thread having a thread leading end in the region of the free end of the shank, whose outside diameter, starting from the free end, increases to a maximum outside diameter and, starting from its maximum outside diameter and continuing toward the torque-receiving means, decreases quasi-continuously to a smaller outside diameter. The thread-core diameter of the shank, starting from a region next to the torque-receiving means and continuing toward the free end of the shank, decreases quasi-continuously to a smaller thread-core diameter of the shank.

Abstract: Provided are a coating agent capable of forming, on the periphery of a tapping screw, a coating layer which can hold female-thread-forming chips generated during screwing of the tapping screw into a prepared hole of a workpiece, thereby preventing scattering of the female-thread-forming chips; and a tapping screw having thereon a coating layer formed from the coating agent. The coating agent is a composition containing, as primary components, calcium montanate or a calcium-montanate-containing montanic acid species mixture, a thermoplastic resin emulsion, and water. The coating agent can form, on the periphery of a tapping screw, a coating layer which exhibits a lubricating function, and a function of capturing female-thread-forming chips.

Abstract: A method for mounting a screw and a thread-armoring element in a receiving thread of a component is described, in which the thread-armoring element is immobilized on the screw and the screw with the thread-armoring element immobilized on it is then screwed into the receiving thread of the component in one single work step. An arrangement comprising a screw and a thread-armoring element immobilized on it for carrying out said method is also described.

Abstract: The invention relates to a self-tapping drill screw that is screwable into a sheet piece and comprises a slotted head for accommodating a tool, a threaded shank, a slightly conically tapering hole-forming part and a hole-grinding part having a conical piece. The hole-grinding part has a radial shoulder that forms a hole and coaxially surrounds the conical piece, engagable with the sheet piece, in a ring-like manner, has a much larger diameter than the conical piece and merges with the hole-forming part via a rounded annular edge.

Abstract: The invention relates to a hole-forming and thread-forming screw for screwing into a sheet piece, comprising a slotted head for accommodating a tool, a threaded shank and a conically tapering hole-forming part, 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 chipless 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 screw includes a transition region (12) located between the screw head and the screw stem and having its circumference formed of from three to ten truncated cones (21, 22, 23) following each other in an axial direction and surface lines of which have different inclination angles (?, ?, ?) toward the axis (A) which diminish from the head (14) in direction of the tip (13), with a first inclination angle (?) of the surface line of a truncated cone (21) located closest to the head (14) amounting to from 40° to 50°.

Abstract: A new and improved fastener wherein the tip portion includes a unique and novel structure that enables and facilitates the insertion of the fastener into both wood and concrete substrates. The tip portion includes a half-cone structure in which a pointed tip is defined between a radially outer conical surface portion and a radially inner flat or planar surface portion.

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.