Abstract: A flexible retainer for retaining die blades in a tool assembly. The retainer comprises inner and outer walls with the inner wall being generally concentric with and radially spaced inward from the outer wall. The inner wall defines a central opening in the retainer which is configured and adapted to extend radially around the die blades so that the retainer retains the die blades in the die assembly while allowing radial movement of the die blades. The retainer may have at least one channel that extends axially between the inner and outer walls.

Abstract: The present invention provides an assembly of sheet materials in which a first sheet of material and a second sheet of material are disposed in an overlapping relationship, with a plurality of joint portions being formed therebetween by drawing an overlapping part of the first and second sheets of materials at a plurality of positions. The plurality of joint portions includes at least one first joint portion in which the first sheet of material is laterally extruded into the second sheet of material and at least one second joint portion in which the first sheet of material and the second sheet of material are in contact with each other in a cup-like surface configuration.

Abstract: A process for the manufacture of cooking vessels, in particular pots and/or pans and the like suitable for magnetic induction heating, is remarkably simple and comprises the steps of: providing a metallic semimanufactured vessel (A) of the cooking vessel, comprising a hollow (21) and a bottom portion (20); providing a plate member (1), in a metallic material of relatively high hardness, provided with a plurality of points (6a, 6b) projecting from a surface thereof (4) and forming an angle (&agr;) equal to or larger than 90° therewith; inducing, by compression or the plate member (1) at the bottom portion (20), the penetration of said points (6a, 6b) and the adhering of said surface (4) of said plate member (1) on said bottom portion (20).

Abstract: As part of a method for producing a combination packaging container (28), which combination packaging container (28) comprises a beaker-shaped plastic inner part (15) and a casing-type outer part (14) surrounding the plastic inner part (15) and retained on the external face of the plastic inner part (15) in an interlocking arrangement, and by which method the two parts (14, 15) are pushed one in the other in an interlocking arrangement, the assembly process is improved due to the fact that the outer part (14) is retained in a holder (13) and the plastic inner part (15) is introduced into the outer part (14) retained in the holder (13) and then pushed down into the outer part (14) so as to interlock.

Abstract: A method of producing metal sections wherein first a groove is made in a section limb by microstructure-changing deformation, then another section limb is placed in the groove and that material of the first section limb which is situated to the side of the groove is moved onto the side walls of the inserted section limb by pressure to such an extent that an at least force-fitting joint between the two section limbs is made at the contact location. This method of microstructure-changing attachment of section limbs makes it possible to produce metal sections with virtually any desired geometry and using any desired starting materials the strength of which sections is comparable to metal sections produced in a previously known manner.

Abstract: A pin and method for fastening the pin in an undercut hole. The pin has an internal end for placement within the undercut hole and an opposite external end that extends away from the undercut hole. The internal end is made from a malleable material such as an annealed material. If desired, the external end can be made from a hardened material. The pin is fastened in the undercut hole by placing the internal end of the pin in the undercut hole and impacting the external end of the pin, thereby causing the internal end of the pin to substantially conform to the interior of the undercut hole and fastening the pin in the undercut hole.

Abstract: The tool, for bonding two plates together, has a punch (1) and a die (2) each as two-part structures with a positive fit between the two parts. One part (8, 13), as a tool which acts directly on the plate workpieces (3), is of a harder material than the other part (7, 12) which acts as a tool holder. The punch and die are divided into their two parts across the working direction.

Abstract: While at least one of first and second tools 4 and 5 of a junction tool 6 is rotated, a workpiece W made of a plurality of plate materials W1 and W2 superimposed in their thickness directions is nipped between the first and second tools and joined at points. The first tool 4 is provided with a pin 44 protruding from its distal end surface 43 along a junction axis X. The second tool 5 is provided with a depression 51 which is depressed at its distal end surface 53 along the junction axis X. By the first pin 44 of the first tool 4 and the depression 51 of the second tool 5, the superimposed surface W3 of the softened workpiece W is caulked in the direction of the junction axis X. Further, plastic flow is generated within the workpiece W so as to agitate the vicinity of the superimposed surface W3.

Abstract: The present invention relates to a joiner for lance joining ductile materials, such as metal sheets, and in particular to a joiner including a die assembly and a punch assembly. The die assembly includes a die anvil and an anvil surface. There are at least two die blades around the anvil, the blades extending in a longitudinal direction, generally above and below opposite sides of the anvil surface to form a die aperture for the punch. Each blade is arranged to move away from the anvil to open up the aperture when ductile material is forced in the longitudinal direction into the aperture and against the anvil by the punch. Each blade has a cutting edge above the anvil facing towards the die aperture for cutting through the ductile material to make a lance joint when the material is forced into the aperture. The assembly also has at least one biasing means by which the blades are biased towards the anvil to constrict the aperture.

Abstract: A progressive stamping die assembly apparatus and method in which strip stock material advances in a first direction through the apparatus and substantially simultaneously with the strip stock movement, a transversely moveable die station moves in opposite second and third directions substantially perpendicular to the first direction to one of a plurality of predetermined positions.

Abstract: A fastener such as a self piercing rivet is inserted into sheet material without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material. The sheet material is disposed between a nose and a die of fastening apparatus. The rivet is inserted into the sheet material by means of a plunger that is reciprocal relative to the nose. Prior to rivet insertion no significant clamping force is applied to the sheet material and material immediately around the rivet insertion location is allowed to flow towards the rivet as to rivet is inserted. Thereafter during a second stage (being after said first stage) of rivet insertion a clamping force of sufficient magnitude is applied between the nose and the die in the region around the rivet insertion location so as substantially to prevent flow of displaced sheet material away from the rivet. The invention may also be applied to panel clinching.

Abstract: A rivet and method for riveting metal members, and particularly, metal sheets is disclosed. The apparatus includes a rivet assembly for driving a piercing rivet into stacked metal sheets and a die for assisting in supporting the sheets during driving of the rivet and for assisting in securing the rivets to the sheets. The rivet of the invention includes an adhesive that is forced through passages in the rivet for assisting in fastening the rivet to the sheets and for assisting in fastening the sheets to each other with greater strength.

Abstract: A fastener such as a self piercing rivet (1) is inserted into sheet material (19) without full penetration such that the deformed end of the rivet remains encapsulated by an upset annulus of the sheet material (19). The sheet material (19) is clamped between a nose (17) and a die (16) of a riveting machine. Once the sheet material (19) is clamped, the distance between the nose (17) and the die (16) is controlled during the riveting operation by a restraint device (20, 23). This technique ensures that reaction forces generated in the joint between the nose (17) and the die (16) during riveting are absorbed in the joint as compressive stresses during the riveting operation so that the resulting joint has improved fatigue life. Furthermore, the rivet insertion load imparted into the C frame as a reaction force is applied back into the joint as a post rivet-insertion clamping load. Alternatively, a separate clamping force is applied after the rivet (1) has been inserted.

Abstract: The invention relates to a method, a tool and a punch (1) for joining a sunken punch to one or more metal plates (2, 3). According to said method, in a single step, the plate or plates are deep-drawn into a deep-draw opening (5) of a female mould or then possibly crushed so that the displaced material fixes and joins the punch (1) to the plate or plates in a positive fit. The punch (1) may present further possibilities for engagement for creating a connection to other components.

Abstract: The present invention enables to firmly assemble a steel-frame structure. To form a steel-frame structure or to join two steel members being reinforcing members thereof, a slip-proof surface having one or plural concentric higher parts and grooves is formed on the joined surface of one side or both sides of the steel members, and these two steel members are clamped by a connecting member that passes through connecting holes in the state where the first and the second slip-proof surfaces are mutually engaged or not engaged. Thus, joining force between the joined surfaces is increased.

Abstract: A process for manufacturing a can with a polygonal cross-section and a can with a polygonal cross-section, the process comprising the steps of milling the cylindrical lateral wall of a tubular body (10), providing said wall with a plurality of circumferential ribs (20) which are continuous and axially spaced from each other and defined by a certain degree of radial plastic deformation of the respective circumferential region of the cylindrical lateral wall of the tubular body (10); expanding the formed tubular body (10), deforming it, in order to define longitudinal edges (12) in whose region the circumferential ribs (20) are eliminated; and double-seaming a bottom and an upper wall of the can to the tubular body (10). This process defines a can having any polygonal cross-section and circumferential ribs (20) on the lateral wall thereof, between the longitudinal edges (12).

Abstract: The invention relates to a method and tool for producing a press joint connection. According to the invention, portions of the radial lateral walls of the matrix opening (3) are configured as flexible displaceable segments, whereas other sections (5), when viewed from the periphery of the matrix opening (3), remain rigidly connected to the die.

Abstract: A process for the manufacture of cooking vessels, in particular pots and/or pans in a relatively soft metallic material, with a plate in a metallic material of high hardness applied to the bottom of the vessel, performs a stable connection among said parts with no mechanical and/or thermal trauma for the materials and comprises the steps of: providing a plate (1) provided with a plurality of points (6) projecting from a surface (4) thereof; inducing, by compression, the penetration of said points (6) and the adhering of said surface (4) at the bottom (20); and stretching said bottom (20), thereby causing the deformation and the clutching of said points (6).

Abstract: A method of fabricating a driveline assembly including the steps of inserting a first member within a second member, heating the first member to a temperature greater than that of the second member and inserting both members into a die. The inner surface of the die includes an interlocking torque transferring profile. Fluid pressure is applied to the inner diameter of the inner member to expand both members into the profile on the inner surface of the die. The inner and outer members are then removed from the die and cooled such that both members are at a common temperature. Because the inner member was at an elevated temperature, and thereby expanded a greater amount than the outer member, cooling of the members results in a clearance between the members that provides for relative axial movement between the inner and outer members.

Abstract: A method and apparatus for clinching metal sheets is disclosed. The apparatus includes a punch assembly for stamping indentations into stacked metal sheets and a die assembly for assisting in supporting the sheets during stamping of the indentations and for assisting in forming the indentations. The punch assembly, the die assembly or both in combination provide energy to at least a portion of the metal sheets prior to stamping. In turn, the energy elevates the temperature of the portion of the sheets such that the indentations can be more effectively formed in the portion and such that the sheets are fastened to each other with greater strength.

Abstract: A method of assembly a brush seal between two components having confronting adjacent surfaces, such as the stator and rotor of a gas turbine, comprises providing a slot in one of the components which slot opens through the confronting surface of that component to face the other component. A flexible brush seal element having a plurality of metallic bristles is pushed into the slot so that the free ends of the bristles project from said surface of the one component. The element is then held in position in the slot by means of an anchoring strip pushed into the slot so as to bear on a wall thereof and also on the brush seal element, the anchoring strip typically being of a malleable metal.

Abstract: A method is disclosed for inserting an end of a first tubular member into a complementary end of a second tubular member and attaching (e.g., welding) the adjacent surfaces of the inserted ends in a tight peripheral bond. In the method, a substantially continuous protrusion is formed in either the first or second member. Thereafter, the first and second tubular members are placed relative to each other such that a current may be passed through the protrusion and a seal may be formed, thereby joining the members.

Abstract: A clenching device for generating a clenching connection between a first workpiece and a second workpiece using a plunger which is movable from above into a recess of a die, wherein a peripheral wall of the recess has stationary wall sections which extend essentially parallel to a pressure direction. The peripheral wall of the recess has between the stationary wall sections movable wall sections which are arranged on levers. The levers are movable by pressures from above into a working position and are securable therein and from undercut areas and are movable by movement of the workpieces after the workpieces have been jointed in the upward direction into a release position in which the undercut areas are completely released.

Abstract: A stud for installation in a host panel and for fastening a component to the host panel includes at least one shaft having a longitudinal axis. An annular flange extends radially from the shaft at a substantially right angle with respect to the longitudinal axis. A shoulder for engagement with the host panel has a top adjacent to the shaft and a base adjacent to the flange. The shoulder extends radially from the shaft wherein the shoulder and the flange define an undercut therebetween at the base of the shoulder such that a diameter of the shoulder is smaller at the base than at the top. At least one anti-rotation tab is located intermediate between the shoulder top and the flange, and is aligned for engagement with the host panel.

Abstract: An apparatus for connecting contact sheets to form a contact body is disclosed, that provides for deforming projection-depression couplings formed in two or more interlocking sheets to form positive locks by which assemblies of sheets are formed. The apparatus includes crimping devices that crimp projection-depression couplings located in the interior area of the interlocked sheets and projection-depression couplings located adjacent the side edges of the interlocked sheets, again to form positive locks by which assemblies of sheets are formed.

Abstract: A method of bonding a magnetic disk drive head suspension to an actuator arm. The actuator arm has a boss hole therein and the suspension includes a base plate with an inside diameter or barrel therein. A thermoplastic cylindrical core is fabricated with a barrel therein. The suspension and actuator arm are clamped together to form a head stack assembly in which the base plate inside diameter is aligned with the boss hole in the actuator arm. The thermoplastic cylindrical core is passed through the base plate inside diameter and the boss hole in the actuator arm. A heating tool, such as an ultrasonic horn is passed through the barrel of the cylindrical core and heated causing the cylindrical core expand and bond to the base plate inside diameter and to the actuator arm boss hole.

Abstract: The invention relates to an article of manufacture comprising a partial or complete tubular primary part defining a tube axis and having an at least partially curved circumferential wall at least partially encircling the axis; said wall comprising a joint edge, defining a) a joint line along said edge on said wall, b) a joint plane drawn to contain said joint line, c) a joining direction having at least a direction component perpendicular to said joint line and said joint plane, d) a locking plane at least partially at the surface or within a section through said wall in which both said joint line and said joining direction lies and e) a normal direction being perpendicular to said joint plane; and at least one locking structure, the improvement comprising that the locking structure includes at least one positive or negative hook structure in said locking plane, extending in the joining direction away from the joint line and having an undercut in the locking plane and that the hook structure is exposed from a

Abstract: Transducer suspensions are attached to actuator arms by means of bonding a portion of a thermoplastic actuator arm to the magnetic recording head suspension assembly. The actuator arm has rail portions that provide a channel in which the load beam and base plate flange fit. The rail portions are ultrasonically welded using a clamping ultrasonic horn, which causes melted plastic to flow over the flange The clamping ultrasonic horn causes heat to be applied and focused at prongs to cause the rails to flow and expand onto the flange rigidly connecting the base plate and load beam to the actuator arm.

Abstract: An exhaust gas sensor is provided and formed by attaching the sensor's upper shield and shell. The attachment is attained by bending a protruding segment or lip over a terminal end portion of the lower shield. This produces a single sealing surface and eliminates the requirement of a conventional crimp which places high compressive forces on the sensing element.

Abstract: An improved connecting rod assembly and method for making a connecting rod wherein the installation of the bearing sleeve members in the large bearing end of the connecting rod is improved. The connecting rod is forged, and then notches are cut in the large bearing end to define a separation plane about which the large bearing end is subsequently separated to form a cap member and a body member. Sleeve bearing members are inserted into the cap member and body member. Free ends of the sleeve bearing members project beyond associated surfaces of the cap and body members a predetermined distance. Upon compressive re-attachment of the cap member to the body member, the free ends of the bearing members are compressed and deformed to provide protrusions that extend into the notch. The protrusions help to prevent rotation of the bearing members relative to the bearing housing.

Abstract: In a motor yoke manufacturing method, a flat metal plate is die-cut into a base plate for a yoke which comprises a bottom wall and a side wall. The base plate is plastically deformed to form a bearing accommodating holder and protrusions on the bottom wall. After a bearing member is placed in the bearing accommodating holder, a resilient plate is placed in contact with the bearing member and the protrusions are plastically deformed to tightly fix the resilient plate to the bottom wall. The base plate is plastically deformed to shape a generally bottomed cylindrical configuration of the yoke. Thus, the yoke is manufactured without a flushing process for removing machining oil or machining debris.

Abstract: The invention relates to a method for manufacturing an electrode for a plasma reactor, comprising the step of interconnecting a support ring and an electrode plate provided with through holes mechanically and electrically by means of a shrink connection, wherein the connecting step furthermore comprises the application of an electrically conductive layer to the joining interface between the electrode plate and the support ring. Furthermore an electrode is provided, wherein said support ring and said electrode include interlocking parts, to the joining surface at which the electrically conductive layer is applied.

Abstract: A joint for joining a first metal sheet (10) to a second metal sheet (30) comprises a plurality of projections (18) on the edge (12) of the first metal sheet (10). The projections (18) are symmetrical about a plane extending perpendicularly to the plane of the first metal sheet (10). The symmetrical projections (18) are rotatable about an axis (X), the axis (X) is arranged in the plane of the first metal sheet (10) and in the plane extending perpendicularly to the first metal sheet (10). A plurality of slots (32) are provided through the second metal sheet (30). The symmetrical projections (18) extend through the slots (32) in the second metal sheet (30) and the symmetrical projections (18) are rotated such that the symmetrical projections (18) are arranged in the plane perpendicular to the plane of the first metal sheet (10) to clamp the second metal sheet (30) between the edge (12) of the first metal sheet (10) and symmetrical projections (18).

Abstract: The present invention provides methods of forming mud motors. In one method, rollers are urgingly stroked against a tubular member having a mandrel therein that has an outer profile which is the inverse of the desired profile of the stator. In another method, rollers are urged and rotated radially on the tubular member with the mandrel disposed in the tubular member. In yet another method, dies are pressed against the tubular member having a mandrel with a desired outer profile. In another method, a molten metal is deposited over a mandrel with an outer lobed surface that is substantially the inverse of the desired inner profile of the stator housing. The mandrel is then removed, leaving a metallic longitudinal member having an inner profile defined by the outer profile of the mandrel. In each of these methods, the inner surface of the resulting member has the profile defined by the outer profile of the mandrel.

Abstract: Rollers and cylinders that are useable in a rotary printing presses are made using hollow tubular casings having metallic foam cores. The casings and cores are made separately. The cores are then placed inside the casing and the two are secured in a force-transmitting manner.

Abstract: In a hemming structure of metal plate material with an edge portion (7) of an outer panel (6) hemmed over an edge portion (2) of an inner panel (1), the edge portion (2) of the inner panel (1) has an inside rise portion (3) having a surface plane (3′) down-sloping towards an edge (4) thereof and the edge portion (7) of the outer panel (6) has an outside rise portion (8) telescopically fitted with the inside rise portion (3), a back plane (8′) of the outside rise portion (8) abutting on the surface plane (3′) of the inside rise portion (3).

Abstract: A method and apparatus for clinching metal sheets is disclosed. The apparatus includes a punch assembly for stamping indentations into stacked metal sheets and a die assembly for assisting in supporting the sheets during stamping of the indentations and for assisting in forming the indentations. The punch assembly, the die assembly or both in combination provide energy to at least a portion of the metal sheets prior to stamping. In turn, the energy elevates the temperature of the portion of the sheets such that the indentations can be more effectively formed in the portion and such that the sheets are fastened to each other with greater strength.

Abstract: An apparatus for connecting contact sheets to form a contact body is disclosed, that provides for deforming projection-depression couplings formed in two or more interlocking sheets to form positive locks by which assemblies of sheets are formed. The apparatus includes crimping devices that crimp projection-depression couplings located in the interior area of the interlocked sheets and projection-depression couplings located adjacent the side edges of the interlocked sheets, again to form positive locks by which assemblies of sheets are formed.

Abstract: A method of assembling together, without welding, first and second pieces of plastically deformable material, said method comprising: in a first step, making a rim hole in the first piece, the hole having a rim with an inside diameter D2i and an outside diameter D2e; a step of making a counterbored hole having two successive diameters in the second piece, said counterbored hole having a first section of small diameter d8 and a second section of large diameter D8, the small diameter d8 being greater than the outside diameter D2e of the rim; a step of inserting said rim into said counterbored hole, an annular gap being defined between the outer annular face of the rim and the inner annular face of the second section of the counterbored hole; and a step of deforming the end portion of the rim so as to occupy at least part of the annular gap; said method comprising prior to the step of deforming the end portion of the rim, a step of inserting centering means in the rim hole, the centering means having a diameter

Abstract: A rebar forming apparatus includes a malleable material supply station for continuously supplying a malleable planar material and a malleable material forming station for forming the malleable material into first and second corresponding shell portions and related rebar products. The apparatus also includes a core pultrusion station and a cladding forming station for respectively forming core and cladding layers. A shell forming station is positioned downstream of the core and cladding forming stations which unites the first and second shell portions to form an outer shell with the core and cladding layers contained therein. The rebar product includes shell portions which are matably configured to form a disposable outer shell over the core and cladding layers. Related reinforcing composite product forming methods also include the use of a removable outer shell.

Abstract: A shock absorbing type steering shaft comprising a tubular outer shaft having a female serration and a solid inner shaft having a male serration. After the outer diameter surface of the outer shaft is pressed inwardly in the radial direction to plastically deform an inner portion thereof, the inner shaft is inserted into the outer shaft so that the inner shaft is pressure-contacted and fixed to the plastically deformed portion of the outer shaft.

Abstract: A bed, more particularly a coffin bed, comprising a rectangular frame formed by a single member formed of sheet metal strip having a tubular section functioning as a beam and a flange extending from the tubular section, and a body support which may be constituted by a piece of plastic netting, attached to the flange, the frame per se, and a method of manufacture thereof involving cold rolling of the strip.

Abstract: The invention relates to a method and a device for achieving adhesion between layers of tissue paper, according to which a surface structure corresponding to that of sandpaper is pressed into the product along the side of at least one roller when the individual layers are joined in a roll nip. This results in good adhesion between layers with only minor optical impairment of the product surface and without the use of glue or such like.

Abstract: A forge/swage formed three dimensional multilayer metal foil shield having areas therein where the layers are in a spaced apart relationship, areas therein where the layers are tensioned or stretched, and areas therein where the layers are compressed and interlocked together by folding, rolling, wrinkling, curling, coiling, crimping and the like. The multilayer metal foil shield is formed by forge/swage shaping in an appropriate mold apparatus a preform of a stack of metal foil layers having gaps between the layers. The gaps are provided by embossments in the layers or by spacers between the layers. The forge formed multilayer metal foil shields have utility as heat shields and acoustic shields, particularly on vehicles. The forge formed multilayer metal foil shields are mounted on automobile underbody areas, such as the bottom of the floor pan of the passenger compartment, to provide heat and sound insulation. Other automotive uses include fire wall, exhaust tunnel, motor mount and exhaust down pipe.

Abstract: A method for securing at least one bearing in a bearing plate provided with an indentation or recessed region for receiving a bearing involves partially swaging at least one positioning face on the bearing plate for accurately or precisely positioning a retaining baffle, positioning the retaining baffle against the at least one swaged positioning face, and materially bonding the retaining baffle to the bearing plate so that the retaining baffle exerts an axial force on a part of the bearing during operation of the bearing. A bearing arrangement includes a bearing plate provided with at least one indentation and at least one partially swaged positioning face, a bearing disposed in the at least one indentation, and a retaining baffle pressed against the positioning face of the bearing plate. The retaining baffle is materially bonded to the bearing plate and is positioned such that the retaining baffle exerts an axial force on a part of the bearing during operation of the bearing.

Abstract: A power assisted combination shear used for forming structural louvers in the crimped seam of structural steel decking comprises a frame supporting a pair of jaws which are opened and closed by means of an operator-controlled pneumatic cylinder. One jaw terminates in a blade and the other jaw has a corresponding die member. The blade and die have undercut reliefs in the root portions, which permit the louver to be formed without breaking through to the edge of the seam. The louver comprises a sheared portion in the form of a bowed tab bridging a corresponding window formed in the seam by the shearing of the tab. The interference between the louver and window provides a substantial increase in the lateral resistance (shear strength) of the crimped seam, thereby obviating the need to additionally weld or screw the seam to provide the necessary shear strength for even the highest stress applications.

Abstract: A secure enclosure (10) for an automated banking machine includes a chest portion (12) and a moveable door (14). The door is supported on hinge assemblies (20, 22) which enable mounting and accurately positioning the door despite misalignment of the hinges. The chest portion is manufactured from panels (28, 36, 38, 66, 76) which include interengaging projections and recesses. The projections and recesses ensure that the proper panels are used in the assembly of the particular type secure enclosure, as well as that the panels which make up the enclosure are properly oriented.

Abstract: The invention relates to a method of attaching an electronic identification device having an electronic identification means to a vehicle body, which comprises the following steps: a) prior to at least one of the steps painting and galvanizing the body, the identification device is attached to the body by means of a spacer in such a way that the identification device is spaced away from the body; b) following painting and galvanizing, the identification device is permanently arrested on the body without being detached in the meantime from the body. The invention further relates to an electronic identification device for being attached to a vehicle body by means of the method proposed.

Abstract: A mechanical assembly process and device for sheet metal parts (30) are disclosed. The material of the metal sheets is displaced and upset out of a sheet metal plane by a forming energy applied by means of a tool set comprising at least one male die (6) and a female mould (4) fitted with an anvil. The forming energy is generated by impact in the form of short, successive strikes.

Abstract: The method of attaching a fastening element to a metal panel within a panel opening using a die member having an annular concave die cavity. The fastening element includes a tubular riveting portion and a radial flange portion and a fastening portion. The internal and external surfaces of the tubular riveting portion are relatively uniformly inclined toward the radial flange portion such that the thickness of the tubular riveting portion at the free end is less than the thickness adjacent the radial flange portion. In the preferred embodiment, the internal surface of the tubular riveting portion is cylindrical and the external surface is slightly conical tapering inwardly toward the free end to reduce the force required to radially deform the free end of the tubular portion radially outwardly.