Abstract: A mine roof support system includes an elongated anchor rod or tendon having a rigid non-deformable distalmost anchoring end portion, and one or more axially deformable portions which are configured to deform in the event load forces exceed a threshold force approximating the forces during a rock burst or rock dilation event. The rigid anchoring portion is provided with primary anchor members such as ribs, grooves, studs and the like. The primary anchor members are configured to reduce bar plasticity, and fixedly secure and retain the rigid portion in place in a drill hole. In the event rock forces exceed the threshold force, the plastically deformable portions elongate with the dilating rock to accommodate and absorb the rock forces.

Abstract: A retrofit system for providing a load indicator on a foundation bolt. The system includes a fastener having a fastener head, gauge length and central fastener bore in the gauge length and head. A datum rod is anchored in the central bore with a free datum rod being moveable longitudinally relative to the fastener head during elongation of the fastener gauge length. An internally threaded fastener portion below the central fastener bore is configured to thread over a foundation bolt. A compression sleeve positioned over the foundation bolt is configured to receive the load indicating fastener therein and to bear the compressive forces of the fastening. Elongation of the gauge length as the fastener is tightened onto the stud is manifest as displacement of the datum rod end, which displacement is measured to provide an indication of fastener loading.

Abstract: A direct tension indicating washer includes a first surface having a plurality bumps formed thereon; a second surface having a plurality of discrete indentations, each indentation formed opposite one of said protuberances; an indicating material positioned in at least one indentation, the indicating material including an indicating material having a first color and an indicating material having a second color; and a channel leading from the at least one indentation to an outer edge of said direct tension indicating washer.

Abstract: Disclosed is a fastener comprising a central elongate shank extending between first and second ends. The first end of the shank has a tapered point. The second end a head has an annular shoulder disposed towards the second end. The fastener further comprises an opposed pair of spines extending helically along the shank and a plurality of hooks extending from each of the pair of opposed spines. Also disclosed is a protrusion extending axially with the shank from the head deformable into an anti-friction washer upon impact by a fastener driver.

Abstract: The invention relates to a threaded fastener. In particular, the invention relates to a threaded fastener such as a nut or a bolt. In an embodiment of the invention, a threaded fastener in the form of a nut (10) is disclosed. The nut comprises a main body portion (12); a lip portion (14) extending from the main body portion; and a recess (16) formed in the main body portion adjacent the lip portion. The recess is shaped to receive at least part of the deformable lip portion when a mating torque is applied to the fastener causing the deformable lip portion to deform. In this fashion, when the fastener is used to clamp two or more components together, such as flanges (20, 22) on adjacent pipe sections, the lip portion encounters a surface of the component that the fastener is being used to clamp against. As the fastener is torqued-up to a desired level, to provide a determined mating force, the lip portion is deformed into the recess in the main body portion.

Abstract: A bolt system for indicating a level of preload of a bolt that is connectable to a subject to be fixed is disclosed The bolt system includes the bolt with a bolt head, a first sleeve attached to the bolt between the bolt head and the subject and a second sleeve attached to the bolt between the bolt head and the subject. The first sleeve is an inner sleeve and the second sleeve is an outer sleeve that fits around the first sleeve. One sleeve is longer than the other sleeve. When the preload is below a maximum value, the longer sleeve transmits the preload between the bolt head and the subject. When the preload is above the maximum value, the longer sleeve is compressed in such a way that both sleeves transmit the preload between the bolt head and the subject.

Abstract: A self-indicating lug nut for use with an automobile wheel stud having an outermost first external thread. The lug nut includes a nut body having an internally threaded bore including a plurality of internal threads, an outermost last internal thread, and an outer end. The lug nut further includes an indicating member removably attached to the nut body proximate to the outer end. The lug nut is configured such that when the lug nut is threadibly advanced onto the wheel stud, interfering contact between the first external thread and the indicating member displaces the indicating member from the nut body. The indicating member can separate into two or more pieces when displaced from the nut body. Displacement of the indicating member provides a visible indication that all of the internal threads of the nut body have engaged the external threads of the wheel stud.

Abstract: A coupling member is employed to couple components of a plasma processing apparatus which processes a substrate by using a plasma. The coupling member includes a threaded rod portion which passes through one component and is screwed and fixed to another component, a head portion which supports the one component and has a diameter larger than that of the threaded rod portion, and an elastic portion which is interposed between the threaded rod portion and the head portion, wherein the elastic portion has a larger strain to an external force than those of the threaded rod portion and the head portion.

Abstract: The invention concerns a device for indicating the tensioning of a fastening member, such as a screw or the like, said device comprising a first portion with a first fastening member receiving aperture; a second portion with a second fastening member receiving aperture in alignment with said first fastening member receiving aperture, and a joining portion connecting said first and second sheet portions allowing the first and second portions are biased towards each other by the head of the fastening member in response to the tightening of said fastening member, wherein the device is provided with irreversible indicator means for indicating that the tension in the elongated fastener during the mounting process has been exposed to a tension exceeded a predetermined tension value, and wherein said irreversible indicator means comprises that said first portion is provided with a distal end portion adapted for sliding and locking engagement with corresponding indicator means provided on the second portion, and that

Abstract: A retrofit system for providing a load indicator on a foundation bolt. The system includes a fastener having a fastener head, gauge length and central fastener bore in the gauge length and head. A datum rod is anchored in the central bore with a free datum rod being moveable longitudinally relative to the fastener head during elongation of the fastener gauge length. An internally threaded fastener portion below the central fastener bore is configured to thread over a foundation bolt. A compression sleeve positioned over the foundation bolt is configured to receive the load indicating fastener therein and to bear the compressive forces of the fastening. Elongation of the gauge length as the fastener is tightened onto the stud is manifest as displacement of the datum rod end, which displacement is measured to provide an indication of fastener loading.

Abstract: A detecting system of a fastening apparatus that detects an axial force of the fastening apparatus including a bolt or a nut. The detecting system includes an axial force detector including a strain gauge and an IC tag, the strain gauge being provided at a predetermined location to detect an axial force value of the fastening apparatus, and the IC tag being connected to the strain gauge and wirelessly transmitting the detected axial force value and unique identification information. Power is supplied to the axial force detector. A reader reads data transmitted from the axial force detector.

Abstract: The invention relates to a threaded fastener. In particular, the invention relates to a threaded fastener such as a nut or a bolt. In an embodiment of the invention, a threaded fastener in the form of a nut (10) is disclosed. The nut comprises a main body portion (12); a lip portion (14) extending from the main body portion; and a recess (16) formed in the main body portion adjacent the lip portion. The recess is shaped to receive at least part of the deformable lip portion when a mating torque is applied to the fastener causing the deformable lip portion to deform. In this fashion, when the fastener is used to clamp two or more components together, such as flanges (20, 22) on adjacent pipe sections, the lip portion encounters a surface of the component that the fastener is being used to clamp against. As the fastener is torqued-up to a desired level, to provide a determined mating force, the lip portion is deformed into the recess in the main body portion.

Abstract: A load indicating fastener comprising a load indicator and a fastener body. The load indicator comprises an annular body defining a through hole having a minimum diameter and a plurality of protuberances integral with a first face of the annular body and a corresponding plurality of indentations in a second face of the annular body opposite from the first face. The fastener body comprises a series of threads, a head defining a contact surface, and a shank depending from the contact surface. The shank includes a first portion having a first outside diameter less than the through hole minimum diameter such that the load indicator is received on the shank first portion and a second portion including at least one radially extending member having a second outside diameter greater than the through hole minimum diameter such that the load indicator is retained on the fastener body thereby.

Abstract: A detection and alarm system comprises a piezoelectric film sensor and associated circuitry. The sensor detects acoustic emission signals from metallic objects under stress upon which it is affixed. The associated circuitry receives electronic signals from the sensor, creates and evaluates a sensor output value including rate ratio and frequency content of such signals within preset time limits. This data allows the detection of impending failure, an alarm condition, of the metallic object by identifying significant changes in the rate of emission of such sensor signals. An alarm condition may then trigger an alarm signal to warn of such impending failure.

Abstract: A laminated nut with a visual indicator indicating if the nut is in a fully tightened state. The nut includes a plurality of conical disc springs enclosed in a cage. In one embodiment, a visual indicator extends axially from the upper surface of the outermost disc spring. In one embodiment, the visual indicator is retracted into the cage when the disc springs flatten as the nut is tightened. In one embodiment, the visual indicator aligns with a reference point on the cage when the nut is fully tightened. In one embodiment, the visual indicator is made more apparent by marking the visual indicator with a contrasting color.

Abstract: A washer has a body having an axis and provided with a first bearing face surface located at one axial side and adapted to cooperate with a nut, a second bearing face surface located at an opposite axial side and adapted to cooperate with an object, at least one third turning resistant surface adapted to cooperate with a thread of the bolt, the body having at least one resistive point arranged so that when the nut is turned and turns the bolt the body of the washer stops the bolt from turning and thereby the nut creates a pull on the bolt which elongates the bolt in an axial direction and applies to the body of the washer an axial force which overcomes the at least one resistive point so that a portion of the body of the washer is allowed to be pulled axially when the bolt elongates.

Abstract: A nut member has first and second end faces and corners, and is formed with a plurality of protrusions, each of which is disposed at a respective corner and each of which has a lateral inner face that extends from the second end face, and a plurality of recesses, each of which is indented inwardly from a respective corner and each of which is defined by a recess-defining wall. The recess-defining wall has a lateral outer face that extends from the first end face. Each protrusion is received in and meshes with a respective recess, and the lateral outer face is in face-to-face contact with the lateral inner face when two of the nut bodies are stacked and are tensioned on a screw bolt.

Abstract: A multi-part, self-drilling, self-tapping fastener with on board, internal chambered adhesive for, permanently connecting a plurality of parts at an overlaid joint thereof having access from one side. The fastener, that drills its own hole through the joint and taps its own threads for mechanically connecting the parts and subsequently extrudes the adhesive under pressure for optimized joint adhesive infiltration and bonding area for maximizing joint strength. The mechanical fastener holds the parts together eliminating the requirement for holding with auxiliary fixtures allowing the parts to be finished and painted during adhesive cure.

Abstract: A nut member includes a polygonal nut body having opposite first and second end faces, and a plurality of side faces extending between and interconnecting the first and second end faces. Each adjacent pair of the side faces cooperatively define a corner therebetween. A plurality of tightness-indicating protrusions are formed on and project axially and outwardly from the second end face of the nut body at positions adjacent to said corners, respectively.

Abstract: A dowel bolt is formed of a bolt (1) and has at the trailing end an outer thread (2) and on the leading end an expansion head (3) expanding in the setting direction (S) and an expansion sleeve (4) that can be expanded by the expansion head (3). At the trailing end face (15) directed away from the setting direction of the bolt, the bolt has at least one peripheral recess (16) with a depth (t1) providing a setting control and that can be economically manufactured.

Abstract: A fastening element is adapted to cooperate with a tie member to exert a compressive force on first and second components. The fastening element has an inner portion (50) resiliently joined to an outer portion (52), such that when a tensile reaction force is applied to the tie member as a result of the compressive force, the reaction force causes the outer portion (52) to be displaced relative to the inner portion (50). The fastening element may further include a washer (56) rotatably attached to the outer portion (52) by a cage (54). An indicator element for use with such a fastening element is also provided, together with a method of securing a first component to a second component by means of such a fastening element.

Abstract: A girt retainer is described for temporarily securing one end of a girt to a column clip until a second girt has been secured to the first girt and the column clip. The girt retainer comprises a threaded shank having a deformable, disk-shaped head mounted thereon. The head has at least one anti-rotation protrusion extending downwardly therefrom. The method of utilizing the girt retainer to temporarily secure one end of a girt to a column clip is also described. The retainer may also be used as a purlin connector or as a connector for connecting the overlapping ends of two elongated members.

Abstract: A system for attaching a structural member to a supporting member, the supporting member having at least one stud which extends through an opening of the structural member, the system comprising a sleeve having as radial flange at one end adapted to be introduced into the opening, an annular sealing element positioned on the sleeve and adapted to engage the associated surface of the structural member, an integral nut arrangement, preferably of spring steel, which has a nut portion adapted to be threaded onto the stud, a fastening portion adapted to be secured to the flange, the fastening portion being rotatable with the flange and engages axially the radial flange of the sleeve, and a deformable portion between the nut portion and fastening portion which allows a certain axial deformation if the nut arrangement is threaded onto the stud with a predetermined torque into engagement with the radial flange, the deformable portion and the fastening portion forming a passage for the stud.

Abstract: A clamp load indicating device (10) for fasteners is made from two flat washers (12) and a tubular crush element (18) mounted between the flat washers. A ring gauge member (14) is interposed between the washers and about the tubular crush element. The camp indicator device is mounted about the shaft (34) of a fastener and when sufficient clamp load is exerted thereon, the crush element crushes to allow the flat washers to engage with the ring gauge member and rotatably affix it with the washers.

Abstract: A fastening element is provided, which is adapted to cooperate with a tie member to exert a compressive force on first and second components, the fastening element comprising an inner portion (50) resiliently joined to an outer portion (52), such that when a tensile reaction force is applied to the tie member as a result of the compressive force, the reaction force causes the outer portion (52) to be displaced relative to the inner portion (50). The fastening element may further comprise a washer (56) rotatably attached to the outer portion (52) by a cage (54). An indicator element for use with such a fastening element is also provided, together with a method of securing a first component to a second component by means of such a fastening element.

Abstract: A connecting element in the form of a screw or bolt, nut or washer for a screw connection has at its bearing surface at least one projection and at least one radially further outwardly disposed surface region. The height and cross-section of the projection are so dimensioned that on tightening of the screw connection the projection is elastically or plastically deformed to such an extent that on reaching a predetermined prestress force the radially outwardly disposed area region comes into engagement. When the screw connection, usual in practice, is tightened up to a predetermined tightening torque, the invention reduces the tolerance range of the prestress force corresponding to the tightening torque. The change in the torque vs. rotational angle differential quotient which occurs when the projection has been sufficiently deformed for the radially outwardly disposed area region to come into engagement may also be employed as criterion for terminating the tightening operation.

Abstract: A free-running-on, locking-off and tension directly indicated locking nut, capable of indicating whether the locking nut is suitably tightened with the required axial tension and preventing the locking nut from becoming loose, includes a body portion formed with a base and a conical seat portion extending upwardly from a central portion of a top of the base, the seat portion having an upper end formed with a vertical outer wall surface, the body portion having an axial hole extending through the body portion and provided with internal threads, and a cap having an axial through taper hole which is smaller than the concial seat portion in height. The axial through taper hole is formed with a conical surface with a large diameter at a bottom thereof, a neck with a vertical surface extending upwardly from a top of the conical surface, and a chamfer extending upwardly outwardly from a top of the neck to form a countersink, the conical surface being configured to fit over the conical seat portion.

Abstract: A tie-down comprising a flexible strap adapted to be wrapped around an object to be tied down, a first member at one end of the strap having a first hole formed therein and a second member to which the other end of the strap is attached having a second hole formed therein in alignment with the first hole. A fastener having a head and a threaded shank is arranged with the head engaging the first member and with the shank extending through the first and second holes and having a threaded end portion projecting out of the second hole. A nut is threaded on the projecting end portion of the shank and engaged against the second member for being turned to act through the fastener for drawing the first and second members together to tighten the strap around the object and place the fastener and the strap under a predetermined tension. The fastener has an indicator for indicating the tension in the fastener and thereby indicating the tension in the strap. The first member is formed for observation of the indicator.

Abstract: An apparatus for yielding rock support in a rock bolt where yielding is achieved by one or more yielding elements at one or more levels of loading.

Abstract: A rock anchor includes an elongate element. A transverse dimension of a portion of the elongate element is enlarged. The transverse dimension is reducible on the application of a suitable force applied to the enlarged portion. The invention extends to a tensioning device for use with the rock anchor and to a yielding anchor assembly which includes the rock anchor and the tensioning device.

Abstract: A force sensor for measuring tightening tension applied to an assembly component having first and second faces and an axis of symmetry includes a ceramic support layer having a mounting side to be secured to the first face and an exposed side carrying a piezoresistive layer having a resistance that varies in response to its deformation. The force sensor may comprise a central metallic layer and an annular metallic layer joined by the piezoresistive layer or at least two separate sensors having angularly disposed longitudinal axes. A machine for tightening the assembly component includes a motor driven socket for torquing the component in accordance with a sensed tightening tension.

Abstract: A container for a fuel tank having an access opening is provided with a closure which fits within a channel in the container to cover the access opening. An elongated bolt has a collapsible cylinder located between the bolt head and the top of the closure to hold the closure to the container. The cylinder is located about the shank of the bolt, and is collapsible above a selected threshold pressure. Under normal bolting conditions, the cylinder is rigid to provide sufficient force to maintain the closure against the tank. Should an abnormal pressure develop within the tank, the closure moves axially along the shank of the elongated bolt, crushing the cylinder and providing additional tank volume to absorb the increased fluid pressure. This reduces the likelihood of catastrophic failure of the closure and also reduces pressure stress on the other tank structures.

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 load-indicating fastener, such as a bolt (10), has a bore (18) which extends from an end face (16) of the bolt and which can receive a gauge pin (30). The gauge pin (30) is free to rotate so that it can be withdrawn completely from the bolt. In use of the bolt, the gauge pin (30) is reinserted into the bore (18) and screwed down until the end of the pin engages the inner end of the bore. As the bolt is tightened, causing elongation of the shank (12) of the bolt (10) and therefore of the bore (18), the user can check the loading on the bolt by periodically rotating the gauge pin (30), to maintain contact between the end of the pin and the inner end of the bore, until the pointer (40) reaches the mark (28) on the end face (16) of the bolt, indicating that the predetermined loading has been reached.

Abstract: A fastening which allows a bolted-on cap to part from a body when excessive pressures develop in a cavity in the body, comprises a nut and bolt arrangement, and includes a weakened tubular spacer surrounding each bolt, between the bolt head and the cap. The wall of the spacer is drilled or scored in its mid-length area. The material and proportions of the spacer, and the proportions of the score or drilling, are so matched in relation to a particular pressure environment, that on excessive pressure developing, the load exerted on the cap causes the spacer to collapse in controlled manner, rather than merely crushing or breaking.

Abstract: A rock bolt comprises a bolt rod secured in a borehole, a retaining plate attached outside the borehole, a bolt head for the retaining plate, and a supporting connection between the bolt rod and the retaining plate. The supporting connection comprises a tubular member adapted to be inserted into the bore hole, the tubular member having an outer end and an inner end, the outer tubular member end bearing on the retaining plate, and a compressively loaded, deformable and upsettable sleeve member accommodated with a clearance in the tubular member and held between a rodside thrust face and a plateside thrust face constituted by a collar adjacent the inner tubular member end.

Abstract: For anchoring heavy machinery to foundations, previously tensioned stress-level indicating bolt connectors are provided. In a top axial cavity of the connector, threads are provided to mount an angularly adjustable stress-level indicating pin. In use, when the design tension stress level is reached and the connector thereby extended, angular freedom or restraint of the gaging pin indicates that the pre-set stress has been reached or exceeded. Indicia angularly arranged on the connector end facilitate adjustment of the pin to provide upper or lower stress levels.

Abstract: A two-piece mount is provided that is adapted to have the two pieces scre together and has a central bore through one of the two pieces for mounting an insert therein. Each of the two pieces of the mount has means for containing adhesive to allow the two mount pieces to be bonded to a composite structure when the two pieces have been mounted relative to the composite structure.

Abstract: An anchoring device for a tension member of an earth- or rock anchor, where a support element transmitting the tensile force is arranged between an anchoring element undisplaceably connected with the tension member and an anchor plate abuttable against a support base, the support element includes a cylindrical hollow body surrounding the anchoring element, whose inner wall has in its lower region projections protruding inward beyond its inner contour, against which the anchoring element abuts in a force-transmitting manner with partial regions of its cross-sectional area. If a predetermined tensile force is exceeded, the support element and/or the anchoring element can plastically deform in the region of their inter-engaging surfaces, so that a relative displacement occurs in axial direction.

Abstract: Disclosed is a fastener assembly fixable to a structural member, the assembly having means to indicate the torque and clamping force of a bolt which forms part of the fastener assembly.

Abstract: Attainment of a predetermined stress in a bolt (10) which is being tightened is indicated by interference with the freedom of a pin (15) to rotate relative to the bolt. The pin extends along a bore (14) from an end of the bolt and the bore lies in that part of the bolt which presents the minimum diameter of the bolt. The invention is especially useful for detecting when the stress to which the bolt is subjected exceeds the elastic limit of the bolt, because the radial contraction of the bore which then occurs is large, relative to the contraction which occurs during elastic deformation of the bolt.

Abstract: To secure roadways and wall surfaces of open cuts and tunnels, a rock anchor assembly is inserted into and secured within a borehole in a receiving material. The rock anchor assembly is made up of an axially elongated tension member laterally enclosed in part by an axially elongated sheathing tube so that the tension member projects outwardly from the opposite ends of the sheathing tube. In the insertion direction, the leading end of the sheathing tube is secured in tension-resistant locked engagement with the tension member. Initially, a hardenable adhesive material is injected into a borehole and then the assembled tension member and sheathing tube are inserted into the adhesive material so that the unsheathed end of the tension member is anchored in the base of the borehole. The trailing end of the sheathing tube has a flange which bears against a anchor plate in contact with the surface of the receiving material in which the borehole is formed.

Abstract: A nut in combination with a deformable plastic plug is provided so as to produce a torsional reistance when the nut is screwed onto a similar male thread such as a bolt. The plug comprises an inner core wedge and an outer sleeve which will expand upon insertion of the core. The sleeve is placed into the nut, leaving at least one complete turn of the thread free, and the core is wedged into the sleeve forcing it to deform into the thread.

Abstract: An expansion dowel includes an axially elongated expansion sleeve, an expansion body and a threaded bolt secured to the expansion body. The expansion sleeve has a leading end arranged to be inserted first into a borehole in a receiving material and a trailing end. The expansion sleeve is slotted in the axial direction from the leading end so that the sleeve expands radially as the threaded bolt draws the expansion body into the leading end of the sleeve. Further, the sleeve has an axially deformable region between the leading and trailing ends. A shoulder extends radially outwardly from the sleeve adjacent the trailing end. A disc is held on the outside of the sleeve spaced axially from the shoulder toward the leading end of the sleeve. During the placement of the dowel, as the expansion body is drawn into the leading end of the sleeve, a minimum anchoring value is reached. After reaching the minimum anchoring value, the sleeve is axially deformed.

Abstract: An expanding bolt anchor with setting force indication, has a slitted expanding sleeve which can be expanded by at least one expander engaging the bore-internal end. In the bore-internal expander (26) there is held a threaded bolt (30) which is carried in a freely displaceable manner through the expanding sleeve (20), and a spacing sleeve (32) adjoining on the bore-orifice end, the bolt terminating in a bolt head (34) or in a nut threaded thereon, under which a washer (30) is disposed which lies on the upper side of a workpiece (10) to be fastened and through which the spacing sleeve displaceably passes.

Abstract: An elongate pin extends in an axial bore in a threaded fastener, at least one end portion of the pin protruding from the bore. An abutment is provided on said one end portion, while when the fastener is in an unstressed condition may rotate about the longitudinal axis thereof. Conversely, when the fastener is subjected to a predetermined tension, rotation of the abutment is prevented by engagement with an end face of the fastener.

Abstract: A rock anchoring arrangement for use especially in tunnel and mine constructions involving considerable convergences comprises an anchoring sleeve having a leading and a trailing end as considered in the direction of introduction of the anchoring arrangement into an anchoring bore in the rock formation, an anchoring rod having a trailing end portion passing through the interior of the anchoring sleeve and a leading end portion which extends beyond the leading end of the sleeve, a mounting plate arranged at the trailing end of the sleeve and engaging the rock formation around the open end of the bore, and a drawing die secured to the sleeve at the leading end. The anchoring sleeve and the anchoring rod are both retained in the bore by a body of a hardenable material, such as an adhesive, in which the sleeve and the leading end portion of the rod are embedded. The leading end portion of the rod has a smaller diameter than the trailing end portion so that a transition region exists between these portions.

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.