Abstract: A spin nut is operable to attach to a threaded fastener such as a rod. The spin nut includes a threaded nut having a shoulder for supporting a bracket, and a snap retainer detachably coupled to the threaded nut operable to spin onto any position on the threaded rod. At least one wing is formed on the snap retainer operable to attach to a bracket having a hole and spin to adjust to a position on the threaded rod. The snap retainer is detachably couple the plurality of sectioned threaded nut sections operable to spring open on a side opposite the band to allow the threaded rod to pass through.

Abstract: The fastener includes a bolt, a nut, a sleeve, and a drive nut. The drive nut interfaces with the nut. The bolt is disposed through the nut, sleeve, and drive nut. The bolt comprises one or more threaded portions and a non-threaded portion. The fastener breaks-off at the non-threaded portion during installation. The installed fastener comprises a recess-free, flush surface with a workpiece.

Abstract: An assembly that includes a first mount, a second mount and a fuse pin. The first mount is configured with a first aperture. The second mount is configured with a second aperture. The fuse pin is mated with the first aperture and the second aperture. The fuse pin connects the first mount and the second mount together. The fuse pin has an axis, and is configured with a plurality of slots arranged circumferentially about the axis. A first of the slots has a length measured along the axis. The second mount has a thickness measured along the axis at an interface between the fuse pin and the second mount. The length is greater than the thickness.

Abstract: An assembly includes a simulated nut-and-washer member and a mounting device. The simulated nut-and-washer member includes a base plate simulating a washer, and a cylindrical portion simulating a nut and having a top surface and an outer sidewall with a plurality of faces, the top surface defining a first circular opening having a first diameter. An inner annular surface is disposed radially inward from the outer sidewall and defines a second circular opening disposed coaxial with the first circular opening and having a diameter that is less than the first diameter. The mounting device is configured to be received through the first and second circular openings, and it has a head portion that is configured to contact the inner annular surface.

Abstract: A fastener system is provided that attaches a connector or other upper member to a lower structural member such as a post or beam. The improved fastener consists of a fastener having an extending shank that is driven into a lower structural member and the fastener is received by a washer that also has an extending tube, and the extending tube of the washer is received by the connector or upper member and is also, preferably received in the structural member.

Abstract: A fastener with a central longitudinal axis, including a grommet including a leg portion which ends with a toe portion, and a pin including a head portion, a tail portion and a body portion, the head and tail portions each having an outer circumference greater than a maximum outer circumference of the body portion, the body portion including a first shoulder defined by first and second beveled surfaces and a first end surface positioned there between, and a second shoulder defined by third and fourth beveled surfaces and a second end surface positioned there between, the first and third beveled surfaces are of different angles relative to the central longitudinal axis, the second and fourth beveled surfaces are of different angles relative to the central longitudinal axis.

Abstract: The invention relates to an assembly made of a compensating tank and a master cylinder for a hydraulic motor vehicle brake system, wherein the compensating tank has two fastening attachments, each with an opening, wherein openings align with an opening in the master cylinder, and the compensating tank is fastened by a detachable connection by a fastening pin that extends through the aligned openings. In order to improve the installation and possible dismantling of the fastening pin, and at the same time to maintain an optimized assembly weight, the invention proposes that the fastening pin be made of plastic and interact in a positive- or force-locking manner with at least one of the openings of the fastening attachments.

Abstract: The present invention relates to both a proceeding and means for, in connection with hole making in a wall (1), for the mounting of items on the moisture-proof walls (1) of a wet area by means of an expandable mounting element (2), providing sealing of the hole. According to the invention, in addition to an expansion (I) of the mounting element (2) behind said wall (1), there is also provided an internal expansion (II) of the mounting element (2) in the receiving hole (3) of the mounting element (2) in question in the wall (1). There is furthermore provided a liquid-proof cover (III) around the entire mounting element (2) in question introduced and expanding in said receiving hole (3).

Abstract: A blind fixation device for attaching an assembly of a pre-drilled member set that includes a rod defining a traction mandrel, a first bushing, and a second deformation brushing. The second deformation bushing is capable of deformation on an inaccessible side of the set of pre-drilled members between the head of the mandrel rod and the end portion of the first bushing. The first bushing is capable of bearing on the accessible side surface of the set of pre-drilled members to be assembled, and is capable of radial deformation so as to come in close contact with the drilling profile of at least one pre-drilled member when, upon assembly, the portion of the mandrel rod initially in the second bushing enters the first bushing.

Abstract: Disclosed are several clamps and a method for installing the clamps through at least two work pieces from one side. The clamps include a shank, a spacer, a core bolt and an expander. The shank and expander are keyed to together with the expander engaged on the core bolt such that rotation of the core bolt can bulb the expander to form a clamp surface on the blind side of the work pieces. The shank and spacer are temporarily held apart until the expander is bulbed wherein the shank is allowed to enter the spacer to clamp the work pieces. Subsequent over torque of the core bolts fractures a weakened portion of the core bolt permitting removal of the clamps when desired.

Abstract: A clamp and a method for installing the clamp into at least two work pieces is provided. The clamp has a shank keyed to an expander. The expander engages the core bolt such that rotation of the core bolt bulbs the expander to clamp the work pieces. A spacer engages the shank to prevent rotation of the shank during installation. The shank has a flange fracturing at a predetermined compression load. The core bolt optionally has a first and a second break groove fracturing at predetermined compression loads. A nut is optionally provided to engage the spacer.

Abstract: A blind rivet design has an exposed mandrel portion modified from the conventional and standardized mandrel to reduce amount and cost of materials required to produce the mandrel, while also minimizing costs related to production, use, and spent mandrel disposal, all while still making use of conventional riveting tools for rivet setting and maintaining rivet performance. The blind rivet also facilitates feeding of a shortened spent mandrel through conventional riveting tools and into mandrel collection devices.

Abstract: Disclosed is a clamp that includes a bolt, a spacer, a shank, an expander and a blocking means. The bolt includes a non-threaded undercut that permits the bolt to rotate in an internally threaded portion of the spacer without threaded engagement between the bolt and the spacer. When used as a clamp, the spacer, shank, expander and blocking means cooperate to deform the expander into a blind side flange and to clamp a work piece between the flange and the spacer. To remove the clamp, the bolt is moved away from the spacer while rotating the bolt in the expander to bring the external threads of the expander into threaded engagement with the internal threads of the spacer. This permits the extraction of the bolt from the blind side expander by maintaining rotational restraint of the expander with the spacer. In several embodiments, a compression spring is positioned between the head of the bolt and the spacer to automatically move the bolt when it is rotated in a loosening direction.

Abstract: The object of the invention is a spreading plug which preferably comprises plastic and has a plurality of slots in the plug cover, between which slots spreading segments are formed which are spread outward against the wall of the drilled hole when a screw or another spreading element is screwed into the central insertion channel of the plug. In order to obtain a plurality of spreading regions which are distributed over the axial plug length, for the purpose of a more uniform spreading action, a plurality of slot arrangements are provided which are arranged offset with respect to one another both in the circumferential direction and in the axial direction. Preferably, a first slot which extends over the diameter of the plug is provided over a part length of the shaft and a further continuous slot is provided, offset in the circumferential direction by 90°, over the remaining part of the plug length as far as the plug base. Here, the two slot pairs overlap one another in the central region.

Abstract: A blind rivet (1) includes a rivet body (3) having a rivet body flange (2) integrally formed therewith, and a mandrel (5) passing through the rivet body and protrudes from the rivet body flange. The mandrel (5) has a large diameter head (6) at the end of the rivet body on the opposite side of the rivet body flange. An external thread portion (13) is provided in a region of the mandrel adjacent to the rivet body flange (2). A sleeve (14) is formed separately from the mandrel (5) and the rivet body (3), and is disposed adjacent to the rivet body flange (2). The sleeve (14) includes a sleeve flange (15) for sandwiching a second attachment member (22) between the sleeve flange and a first attachment member (21), and a deformable swageable portion (17) to be deformed radially in a region of the external thread portion, so as to form an internal thread portion (33) in the inner surface thereof. The rivet body (3) and the mandrel (5) are retained as attached to the first attachment member.

Abstract: An expansible plug has a plurality of expansible tongues which extend over an expansible region and are expandable radially away from one another under the action of an expanding member, the expansible region being radially oversized.

Abstract: Extended fatigue endurance and high pre-load are achieved in a structural blind fastener by combining the best features of screw type and pull type blind fasteners. We replace fatigue critical details from the shear plane with close tolerance, slip fit, core bolt and outer bolt shanks to obtain the desired structural load paths while retaining anchoring features of screw type fasteners to introduce adequate pre-load. These fasteners are compatible with currently available blind bolt insertion tooling.

Abstract: We achieved extended fatigue endurance and high pre-load in a structural blind fastener by combining the best features of screw type and pull type blind fasteners. We replaced fatigue critical details from the shear plane with close tolerance, slip fit, core bolt and outer bolt shanks to obtain the desired structural load paths while retaining anchoring features of screw type fasteners to introduce adequate pre-load. Our fasteners are compatible with currently available blind bolt insertion tooling. The present invention pertains to a lightweight version of the structural blind fastener wherein we set the backside anchor collar with matching threads that engage between the outer sleeve bolt and inner core bolt.

Abstract: An optical axis adjustment structure which includes an aiming adjustment screw having a ball part disposed at one end thereof for receiving and being supported by a movable part of a lamp or the like, an intermediate part screw-engaging with a nut member fitted in a stationary part of a vehicle body or the like, and an operating part disposed at the other end thereof for a rotational operation, and the outer dimension of the operating part of the aiming adjustment screw is designed to be larger than the threaded intermediate part of the screw and the outer diameter of the ball part is larger than the diameter of the threaded part of the screw, while the nut member is integrally molded with the aiming adjustment screw at the intermediate part thereof.

Abstract: The expansion dowel includes an expansion sleeve (1) and an expanding member (5). The expansion sleeve 1 is provided with a bore (2) tapering in the setting direction as well as with open ended longitudinal slots (3). The expanding member (5) has a blind bore (6) open towards the setting side and has a lug (7) projecting from same at its opposite end, wherein the cross-sections of lug (7) and blind bore (6) are matched in such a way to one another, that a rated break point or failure point is formed. The force dependent response of this rated break point leads to a force dependent expansion while maintaining the driving or advance travel (X).

Abstract: In general a blind fastener for securing workpieces is shown and which blind bolt has a core pin with a blind side head and a plurality of threads or locking grooves and a nut adapted to be threaded onto the pin threads; the blind bolt which has a main sleeve structure and an expandable blind side sleeve structure is set by a relative axial force applied to the pin which forces the expandable sleeve structure against the main sleeve structure causing the expandable sleeve to expand and form a load bearing blind head; the blind fastener includes a grip adjuster structure which defines a cavity having a depth selected to define the grip range of the fastener with the grip cavity generally located externally of the workpieces; the core pin head acts on the expandable sleeve and main sleeve structures to cause a frangible portion in the grip adjuster structure to shear and receive the main sleeve structure after which the blind head engages the blind side of the workpieces, with none of the clamp load developed b

Abstract: A threaded fastener and method of fabrication thereof wherein the fastener or nut includes a first portion having external, wrench-engaging surfaces and a central, through bore, internally threaded for at least a portion of its length from a base surface. A wall portion extends integrally from the end of the first portion opposite the base surface, concentrically surrounding and spaced radially outwardly from the end of the bore. The first and wall portions are formed as a metal casting with the wall portion in two segments separated by longitudinally extending, V-shaped notches. The free edges of the wall segments, which initially lie in a plane normal to the axis of the bore, are deformed by a die, moving radially inward so that the wall segments are in a domed configuration with the free edges defining a substantially oval opening having a major axis with a length about equal to the diameter of the bore and a minor axis about 4/5 that of the major axis.

Abstract: A device for a bore formed in a geological structure, the bore having an outer circumferential wall. A bolt is inserted into the bore. A sleeve secures a first axial portion of the bolt to a first portion of the circumferential wall. Grout secures a second axial portion of the bolt means to a second portion of the circumferential wall; A substantially disk shaped plug limits a passage of grout to between the first axial portion of the bolt and the first portion of the circumferential wall. A retainer is included to retain a grout container in the bore prior to insertion of the bolt means into the bore.

Abstract: Disclosed is an anchor assembly especially for use in a plastic wall-panel which comprises a plug formed of a forward section comprising a tapering plastic board-piercing part and an integral ram head, and of a hollow cylindrical section pivotably connected to the forward section. The assembly may further comprise a spike capable of being driven into the hollow cylindrical section, the spike being provided with a cylindrical portion having serrations on its outer surface for bitting into the cylindrical section or ram head and thus being secured to this section or head. The spike is provided with a hammer portion having a length sufficient at least to engage the ram head, as it is driven into the plug, and to cause pivotal of the forward section of the plug and abutment thereof against the concealed side of the plaster-wall panel.

Abstract: A hinge pin is temporarily held on a first hinge member on the automobile body by means of a hinge pin support mechanism. A door to be attached to the automobile body is held in position, and a second hinge member on the door is brought into engagement with the first hinge member. The hinge pin is pressed into the second hinge member through the first hinge member to couple the door to the automobile door. The hinge pin support mechanism includes a hinge pin retaining member including a ring separably joined to a plurality of legs. When the hinge pin is pressed into the hinge members, the ring is sheared off from the legs and rides in a peripheral groove defined in the hinge pin. The ring then engages one of the hinge members to prevent the hinge pin from being removed from the hinge members. The door can automatically be attached to the automobile body by a door attaching mechanism and detached from the automobile body by a door detaching mechanism.

Abstract: An expansible plug to be percussion anchored in a borehole that tapers outward at an inner end thereof comprising an expansible sleeve, expansible segments arranged at an expandable end of the expansible sleeve, an expander member for penetrating into a converging inner bore of the expansion sleeve to expand the expansible segments, and at least one spacing element arranged at an end side of the expansible segments.

Abstract: A fastener-receiving member is disclosed that can be used with either a blind hole or a hollow wall. In addition, the length of the fastener-receiving member can be adjusted to be accommodated within various thicknesses of walls. The nut portion of the fastener-receiving member is configured so that it has ridges at its outer periphery that will engage with the surface of a hole regardless of the quality of the drilled hole. A wing-like locking section will expand to insure an adequate grip between the wall and the member. In addition, an insertion tool is disclosed that aids an operator in inserting the fastener-receiving member into a hole.

Abstract: A cone expansion wall plug is provided comprising a threaded rod, an expansible socket, an expansion cone, an intermediate ring and a spacer between the head of the rod and said intermediate ring. During expansion and anchorage of the socket by the cone, the ring and the spacer prevent movement of the socket with respect to the rod. After anchorage, the rod may be screwed into the cone by shearing a collar of the spacer. During expansion, the socket only bears against the intermediate ring through a radial shoulder.

Abstract: An expansion fastener comprises a female member including a cylindrical portion, a flange portion and a plurality of elastic leg portions, and a male member including a shaft portion to be fitted in the cylindrical portion, a head portion provided at the upper end of the shaft portion and a leg portion expanding portion for causing outward deformation of the elastic leg protions. The cylindrical portion of the female member has a reduced-thickness break portion which extends along an overlap plane along which two plates overlap each other, and a radially inwardly constricted break portion is provided between the shaft portion and head portion of the male member.

Abstract: Apparatus for assembly with a bolt or screw upon installation thereof to prevent tampering therewith, including a one piece collar device having an outer annular jacket member with a restricted collar portion and an inner annular washer member detachably joined to the jacket member at the collar portion by a frangible diaphragm. The stem of a bolt or screw is inserted through the collar device and tightened into engagement with the collar portion to cause shearing of the diaphragm to separate the washer and jacket members, the washer member being of a larger axial dimension and smaller radial dimension than the collar portion to permit the jacket member to rotate freely about the bolt or screw and the washer member when the enlarged fastener head is tightened into clamping engagement with the washer member. A cap member fits snugly in the free end of the jacket member to enclose the fastener head.

Abstract: A securing device for securing in cavaties and comprising a number of clamping jaws (11), provided under influence of a changeable tension body (21) to expand against opposite wall portions (13) in said cavity. The clamping jaws (11) have engagement surfaces (12) which are forced outwards and tension surfaces provided to cooperate with a tension surface (22) of the tension body. By means of a displacement motion of the clamping jaws relative to the tension body is brought to adjust the clamping jaws between an inner releasing position, and an outer expanded securing position. The device comprises a spring mechanism (4) provided to press the clamping jaws (11) in direction against the tension body (21). Between the clamping jaws and the tension body a distance element (20) is positioned being provided to maintain in its releasing position a predetermined distance between a support surface (19) of each clamping jaw and a surface (23) of said distance element.

Abstract: An elongated rod with an expansion shell assembly positioned on the upper end thereof is advanced into a bore hole drilled in rock formation behind a resin cartridge system. The lower end of the rod is connected by a coupling to the upper end of a bolt having a bearing plate positioned on a lower end of the bolt emerging from the bore hole. Unitary rotation of the rod and bolt in a preselected direction while maintaining the shell assembly in an unexpanded condition effects mixing of the resin components in the bore hole. Continued rotation of the rod and bolt after the resin components are mixed effects expansion of the shell into engagement with the wall of the bore hole to anchor the rod in the bore hole.

Abstract: An elongated rod with an expansion shell assembly positioned on the upper end portion thereof is advanced behind a resin cartridge system into a bore hole drilled in a rock formation. A bearing plate and a stop nut are positioned on the end of the rod emerging from the bore hole. Unitary rotation of the nut and rod in a preselected direction while maintaining the shell assembly in an unexpanded condition effects mixing of the resin components. Continued rotation of the nut and rod after the resin components are mixed effects expansion of the shell into engagement with the wall of the bore hole to anchor the rod in the bore hole. The rotation applied to the nut after setting of the shell permits the nut to advance on the lower end of the rod to urge the bearing plate into compressive relation with the rock formation to put the rod under tension without interrupting rotation to allow the mixed resin to cure.

Abstract: An expansion anchor assembly for use in a bore with an undercut section adjacent the base of the bore, includes an axially elongated expansion sleeve and an anchor bolt positioned within the sleeve with an expansion cone at one end of the bolt. The expansion sleeve is slit from one end for a portion of its axial length. By drawing the expansion cone into the slit end of the sleeve, the sleeve can be expanded. An expansion element is seated within a recess in the outside surface of the sleeve. The base of the recess has a decreasing depth in the direction toward the slit end of the sleeve. The expansion element secures the expansion anchor assembly within the bore.

Abstract: An anchor dowel assembly includes an axially elongated sleeve with window-like openings extending through its wall transversely of the axial direction. Locking members are positionable within the window-like openings for displacement radially outwardly from the sleeve for effecting the anchoring action. The locking members are displaced radially outwardly by an expansion tool driven between the locking members by a force directed in the axial direction of the sleeves.

Abstract: An expansion dowel assembly is made up of an axially elongated generally cylindrically shaped dowel body and at least one wedge-shaped expansion member formed monolithically with the dowel body. The dowel body has a first or leading end which is inserted first into a borehole within which the dowel body is to be anchored and an opposite second end. A severable web connects the expansion member to the first end of the dowel body. Before insertion into a borehole, the expansion member projects outwardly from the exterior surface of the dowel body. When the expansion dowel assembly is inserted into a borehole, the web is broken and the expansion member, now separated from the dowel body, is displaced away from the first end within a wedge-shaped recess in the exterior surface of the dowel body.

Abstract: End members for flexible connectors for bicycle pumps are provided, a first end member is fixed to one end of a flexible tube and to be connected to a valve of a tire and the second end member is to be connected to the other end of the flexible tube for connection to a pump. The first end member is made of one piece of molded construction and, at one side of a middle zone has an anchoring stub which carries a cap at its free and by means of at least two frangible bridges. At the other side of the middle zone the first end member has means for linking the connector with the valve of a tire. The middle portion also has resiliently deformable portions for holding the connector in a bore in the handle of the pump. For assembling the first end member with the tube, the cap is fitted over an end portion of the tube and, the bridges are severed and the anchoring stub is engaged inside the flexible tube.

Abstract: A mechanical anchor including an expansion shell and a camming plug positioned in the shell is threaded onto the end of a mine roof bolt. A roof support plate is carried on the opposite end of the bolt. The mechanical anchor is inserted in a bore hole drilled in a rock formation with one or more resin cartridges advanced by upward movement of the bolt to the end of the bore hole. The cartridge is ruptured by upward thrust and rotation of the bolt to release the resin components for mixing. A stop device extending through the plug abuts the end of the bolt to prevent axial movement of the plug on the bolt when the bolt is rotated in a preselected direction to mix the resin components before the shell is expanded. Rotation of the bolt continues without expansion of the shell for a period of time to permit formation of a curable resin mixture.

Abstract: An expansion anchor assembly is made up of an anchor bolt and an expansion sleeve encircling and secured in an annular recess on the bolt. Adjacent the annular recess, the anchor bolt has a frusto-conical section. The expansion sleeve has diametrically opposite reduced thickness wall sections with a projection extending outwardly of the surface of the sleeve along each of the reduced thickness wall sections. When the expansion anchor assembly is inserted into a prepared borehole and the frusto-conical section is drawn into the sleeve, the sleeve breaks into axially extending sections along the reduced thickness wall sections and a uniform contact is provided between the sleeve section and the borehole surface.

Abstract: Base thrust anchor assembly for use with roof bolts and base plate having means to provide deep penetration of the rock strata and provide large areal distribution of the longitudinal load in order to prevent overstressing the rock strata. The assembly employs anchor wings having a small longitudinal cross-sectional area that is applied in a transverse (radial) direction to permit deep penetration of the strata of a bolt hole wall, and a large transverse cross-sectional area to better support the longitudinal load imposed on the rock strata.

Abstract: A mechanical anchor including an expansion shell and a camming plug positioned in the shell is threaded onto the end of a mine roof bolt. A roof support plate is carried on the opposite end of the bolt. The mechanical anchor is inserted in a bore hole drilled in a rock formation with one or more resin cartridges advanced by upward movement of the bolt to the end of the bore hole. The cartridge is ruptured by upward thrust and rotation of the bolt to release the resin components for mixing. A stop device extending through the plug abuts the end of the bolt to prevent axial movement of the plug on the bolt when the bolt is rotated in a preselected direction to mix the resin components before the shell is expanded. Rotation of the bolt continues without expansion of the shell for a period of time to permit formation of a curable resin mixture.

Abstract: A self-drilling dowel is formed by a tubular member defining an axially extending bore. The tubular member has a leading end and a trailing end with a cutting head at the leading end. A spreader member is insertable into the bore for expanding the tubular member. A member, preferably a plate, is positioned within and extends transversely across the bore adjacent the leading end forming a closure. The bore closure member is spaced axially from the leading end and it is separate from the tubular member and is displaceably fitted within the bore.

Abstract: A technique is provided for engaging and disengaging burnable poison rods from the spider in a fuel assembly. The cap on the end of each of the burnable poison rods is provided with a shank that is received in the respective bore formed in the spider. A frangible flange secures the shank and rod to the spider. Pressing the shank in the direction of the bore axis ruptures the frangible flange to release the rod from the spider.

Abstract: A fastening element assembly consists of an anchoring bolt and a spreading wedge. After the assembly is inserted into a prepared borehole, by driving the spreading wedge inwardly relative to the anchoring bolt, the bolt is secured in the borehole. To ensure that it is driven into the borehole for a sufficient distance, the spreading wedge is provided with a separating web intermediate its ends so that if a predetermined breaking point of the separating web is reached, the web breaks and the rear part of the wedge can be driven into the borehole relative to the forward part.

Abstract: A hollow wall fastener using a conventional toggle bolt and a toggle anchor which is pointed and which has an open groove for receiving the toggle bolt. An end cap within the anchor has an internally threaded head portion and a frangible portion which allows the head portion to separate from the rest of the end cap when the end of the bolt is threaded into the head portion, thus twisting the frangible portion until it breaks. Thereafter the head portion prevents withdrawal of the toggle bolt from the anchor. The end of the groove has a threaded portion which cooperates with a threaded portion of an aperture opposite the groove to permit the anchor to pivot with respect to the bolt to a position where the bolt is threadably engaged and locked in the threaded portions of the anchor, forming a "T" configuration behind the surface of the hollow wall. Thereafter the bolt may be rotated to draw the anchor tightly against the interior of the hollow wall.

Abstract: The invention relates to a fixing device for securing any part to a holding member. The fixing device comprises spreadable means in a hole or bore formed in the holding member on the one hand, and on the other hand spreading means. An actuating means is provided to drive the spreading means into the spreadable means so that depending on the length of penetration of the spreading means thereinto the fixing device can be blocked on the holding member and accommodates any thickness variations of said holding member. The invention is used to secure by means of a screw or rivet any part on a holding member such as a panel.

Abstract: A fastener for use with a connecting element such as a screw comprises a thickened head of a firm but plastic material, a shank, and a tail. The head and shank are first placed into a hole; then a connecting element such as a screw is inserted alongside of the head to cause the head to wedge into the wall of the hole and hold the screw tightly. In one aspect the shank and tail are connected by an indented portion that facilitates breaking away the tail and indicates the desired depth of insertion of the head, and in another aspect the head contains a second, harder material to facilitate the wedging action of the head.