Abstract: The invention relates to a friction weld assembly of a plurality of superposed plates, said plates being held together by a connection body which rests on the upper plate by means of a collar and is formed as a slender cone ending in a tip. The connection body comprises a driving element in the region of the collar thereof, for the attachment of a pressure and rotation tool. A girder formed from the slender cone and penetrating from the upper plate into the lower plate, and a girder protruding from the lower plate along the inner surfaces thereof, form a friction welding region extending onto the slender cone.

Abstract: Embodiments of the present disclosure include a system for creating a lattice type structure using friction forge bonds to connect the tower members. The system includes a rotary actuator for engaging and rotating a fastener to create frictional heat at a forge interface between the fastener and two or more workpieces. The system also includes a press that forces the fastener against the workpieces to be bonded, and a heater that may provide additional heating of the fastener and the opening.

Abstract: Two structural components, such as a gas turbine rotor hub and a rotor blade, are integrally joined to each other by friction welding, particularly linear friction welding. For this purpose, each component is provided with a joining surface and at least one of the two components is provided with a groove next to the respective joining surface. The groove extends fully or partly around the respective joining surface and serves for reducing stress in a normal and radial direction of the respective joining surface, whereby a more uniform heating of the joining zone is achieved and joining faults are avoided or at least reduced during the friction welding.

Abstract: A system, in certain embodiments, includes a backing plate, a tungsten-based member disposed along the backing plate, wherein the tungsten-based member defines a welding work surface, and the tungsten-based member comprises curved grooves configured to secure the tungsten-based member to the backing plate. The system also includes a drive. The system includes a pin tool movable by the drive to create friction along one or more workpieces disposed on the welding work surface, wherein the frictional heating and mechanical stirring is configured to create a stir weld along the one or more workpieces. The system, in some embodiments, also may include a backing plate comprising liquid passages and gas passages and a tungsten-based member disposed along the backing plate, wherein the tungsten-based member defines a welding work surface.

Abstract: A system and method for using friction stir welding, friction stir processing, and friction stir mixing to create pressure vessels, pipes or other containers comprised of a single material or multiple layers of different materials, and having superior strength and endurance characteristics.

Abstract: A method of forming a metallic container includes the steps of providing body and lid portions, placing the body and lid portions together, keeping portions of the body and lid portions in contact with one another, and reciprocally rotating the lid portion with respect to the body portion, thereby generating frictional heat and forming a friction weld therebetween. An apparatus for attaching the lid and body portions of a metallic container includes a base to support the body, a support assembly to support a flange of the body, and a sonitrode for contacting a flange of the lid, wherein the flanges of the lid and body are held together between the support assembly and the sonitrode. A motor reciprocally rotates the sonitrode relative to the support assembly, thereby moving the flanges relative one another to generate frictional heat and create a friction weld therebetween.

Abstract: A friction stir welding apparatus and a method of operating the friction stir welding apparatus are disclosed. The friction stir welding apparatus includes a rotary tool whose extremity constitutes a probe, a retaining arm which supports the rotary tool, and a roller provided at a position of the retaining arm opposite the rotary tool. The method includes adjusting the retaining arm so as to position workpieces between the rotary tool and the roller while adjusting the roller to turn in a direction where a joint line of the workpieces extends, rotating the rotary tool and lowering the probe until the probe presses the workpieces, gradually inserting the probe into the joint line, and moving the probe along the joint line.

Abstract: Apparatus and methods for clamping and controlling flash around a manufacturing tool engaging a workpiece and preventing fill within the workpiece. In one embodiment, a clamp for securing a workpiece during a manufacturing operation includes a housing and a foot biased away from the housing, the foot defining an opening through which a manufacturing tool may pass to engage the workpiece. In another embodiment, the manufacturing tool is a rotating or counter-rotating shoulder friction stir spot welding tool. In accordance with other aspects of the invention, the foot defines at least one recess for holding flashing.

Abstract: A friction stir welding device for welding an article by means of a welding tool, includes: a tool holding section configured to hold the welding tool and rotate round a predetermined reference axial line; rotation driving unit configured to drive the tool holding section to rotate round the reference axial line; movement driving unit configured to drive the tool holding section to move along the reference axial line; and a car body loaded with the tool holding section, the rotation driving unit and the movement driving unit, the car body being configured to travel above or below the article.

Abstract: Friction welding systems and methods including a welding arrangement configured to impart kinetic friction between at least one surface of a first workpiece and at least one surface of a second workpiece to form a weld, a force providing mechanism arranged and disposed for applying a force to one or both of the first workpiece and the second workpiece, and a sensor arranged and disposed to measure a parameter of the welding arrangement, wherein an amount of vibration is determinable from the measured parameter.

Abstract: A multi-shouldered friction stir welding tool (10) comprises an integral shank-pin unit (11) having a plurality of pin portions on the shank-pin unit, where the plurality of pin portions for driving into a plurality of joints to perform a friction stir welding operation on the corresponding plurality of joints and, where a shank portion of the shank-pin unit is for attachment to an optional axial tension rod (19), each of the friction stir welding modules comprises a pair of shoulders (13, 14) that is connected to the shank-pin unit where each shoulder has a distal end and a proximal end, where the proximal end of each shoulder faces the pin portion of the shank-pin unit, whereby the shoulder and pin(s) rotate in unison, and a pair of split collars or a pair of nuts that is connected to the shank-pin unit and faces the distal end of each shoulder, where the plurality of friction stir welding modules are connected to each other whereby the modules rotate in unison to simultaneously make a plurality of parallel

Abstract: An object of the present invention is to provide a method for producing a composite material that can prevent a powdered additive to be mixed from scattering and control a quantity of the additive dispersed in the composite material. A method for producing a composite material in which an additional material different from a base material is dispersed into a part of the base material comprises the steps of providing a wire rod formed by applying a metallic film to the additional material to be dispersed or by stuffing a metallic tube with the additional material to be dispersed, fixing the wire rod on a surface or into an inside of the base material, and applying stirring along the fixed wire rod with a tool for friction stirring to disperse the additional material into the part of the base material.

Abstract: A method of splicing a trailing end of a downstream metal strip to the leading end of an upstream metal strip. The method has the steps of overlapping the leading end of the upstream strip with the trailing end of the downstream strip, and thereafter friction welding the overlapping ends together at a plurality of spots at which respective spot welds are thereby formed.

Abstract: It is an object of the invention to reduce mixing of an impurity from a friction stir welding tool, reduce abrasion of the tool, and prevent the tool from being easily broken even though an object to be worked formed by a metal or an alloy having a high melting point of 1350° C. or more is friction-stir-welded. The friction stir welding tool according to the invention can friction-stir-weld a metal or alloy having a high melting point of 1350° C. or more as an object to be worked. At least a portion brought into contact with the object to be worked has a composition containing iridium, containing rhenium, ruthenium, molybdenum, tungsten, niobium, tantalum, rhodium, or two or more of them, and containing zirconium, hafnium, lanthanum, cerium, samarium, gadolinium, scandium, yttrium, or two or more of them, and has a Micro Vickers Hardness of 300 Hv or more.

Abstract: Two aluminium alloy work-pieces are welded together. Firstly, a portion (2) of each work-piece (1) is prepared, the preparation including the performance of a surface treatment, such as friction stir welding, that results in a region (A) extending from the exterior surface into the work-piece having a grain structure that is finer than the grain structure of the work-piece outside (region C) that region. Then the work-pieces are welded together by means of a fusion welding process, such as electron beam welding, that joins the respective prepared portions (2) of the two work-pieces (1). The preparation of the work-pieces is so performed that said region (A) extends into the work-piece to a depth that exceeds the depth of material (region D) that is caused to melt during the fusion welding process.

Abstract: A friction surfacing apparatus and method for depositing one or more metals, metal alloys, or other materials is disclosed. The friction surfacing apparatus includes a pin tool holder, a non-consumable shoulder having an inside diameter and an outside diameter, the inside diameter terminating at an end wall and includes an angled side wall that forms a substantially frustoconical opening at one end, and a consumable pin tool coupled to the pin tool holder and at least partially protruding from the end wall of the shoulder. The shoulder is maintained at a predetermined distance from a surface of a workpiece such that the consumable pin tool deposits pin tool material onto the surface of the workpiece during a friction surfacing operation.

Abstract: Device for joining faces of parts having great longitudinal extension by friction welding. The device includes first and second clamping arrangements structured and arranged to position ends of the parts against one another. At least one of the first and second clamping arrangements is axially movable with respect to another of the first and second clamping arrangements. At least one of the first and second clamping arrangements is movable along a direction that is parallel to a part cross-sectional plane defined by an end face of one of the parts.

Abstract: A rotary friction welding machine and method is disclosed. The rotary friction welding machine has a first rotating spindle and a second non-rotating spindle, where a first component of the components being connected to one another is positioned on the first spindle and a second component of the components being connected to one another is positioned on the second spindle. Several flywheel mass bodies are positioned on the rotary friction welding machine, where the flywheel mass bodies cooperate with the first rotating spindle such that at least one of these flywheel mass bodies can be brought out of operating engagement or into operating engagement with the first rotating spindle, where both the flywheel mass bodies that are in operating engagement with the first rotating spindle and the flywheel mass bodies that are out of operating engagement with the first rotating spindle are positioned on the rotary friction welding machine.

Abstract: A friction stir welding device may include a rotatable head, a rotatable upper shoulder, a lower shoulder and a pin device. The rotatable head includes a first multisided connection portion. The rotatable upper shoulder includes a first cavity and a second multisided connection portion. The second multisided connection portion is configured to engage the first multisided connection portion. The lower shoulder includes a second cavity and a third multisided connection portion. The pin device includes a first end and a second end. At least a portion of the second end includes a fourth multisided connection portion. The fourth multisided connection portion can be configured to engage the third multisided connection portion. The pin device may be configured to retractably traverse the rotatable upper shoulder via the first cavity. The rotatable upper shoulder, the pin device and the lower shoulder may be configured to friction stir weld a workpiece.

Abstract: A friction stir welding tool is used in welding structures. The tool comprises a shoulder and a probe extending from the shoulder. The probe has at least three sections equiangularly arranged around the longitudinal axis of the probe, each section comprising at least three contiguously arranged flats arranged about the axis of the probe. The flats are so arranged that the normal axes of the flats converge in a direction towards the axis of the probe thereby resulting in the sections each having a generally convex shape. The probe also includes a threaded portion disposed between each pair of adjacent generally convexly shaped unthreaded sections.

Abstract: Friction stir welding tool to facilitate stress reduction within the tool that may include a body, a pin, a tension member, and an end assembly, the tension member and end assembly facilitating axial compression of the pin. The tension member may be decoupled from the pin and/or body of the tool via one or more decoupling members. The end assembly may comprise spring members to provide an axial force to the tension member. The pin may include various features to facilitate stress reduction proximal the pin.

Abstract: A counter-rotating spindle includes a shoulder tool, a pin tool inserted in the shoulder tool, a first motor that is connected with the pin tool and rotates the pin tool, and a second motor that is connected with the shoulder tool and rotates the shoulder tool. The direction and the speed of the rotation for the pin tool may be selected independently from the speed and direction of rotation of the shoulder tool enabling optimization of the friction stir welding process. Counter-rotating the pin tool and the shoulder tool may improve the mixing abilities and efficiency of the pin tool and may prevent the galling effect between the pin tool and the shoulder tool. The counter-rotating spindle may be used, for example, for continuous path friction stir welding and spot welding of aluminum and its alloys, including cast alloys, as well as joining similar and dissimilar alloys.

Abstract: An object of the present invention is to provide a friction stir welding tool which enables friction stir welding of a wide range of materials, from low-melting temperature metallic materials including aluminum to high-melting temperature metallic materials including steel. An entire friction stir welding tool or a tool tip including a pin is made of Mo alloy having a dual phase microstructure of Mo and intermetallic compound Mo5SiB2. It is desirable that the Mo alloy be composed of 6.0 to 10.0 mol % of Si, 10.0 to 20.0 mol % of B, and 20 to 60% of Mo-phase volume content. This Mo alloy tool has excellent high-temperature strength and wear-resistance properties and hardly deform and wear when used for the welding of steel.

Abstract: In a frictional spot joining where plural metal members lapping over are jointed with a joining device comprising a rotating tool, a receiving tool disposed on a rotational axis of the rotating tool and a drive device to rotate and move the rotating tool in a pushing direction, a holding member is provided on a side of the receiving tool, which has a restriction portion to restrain a movement of the receiving tool in a direction perpendicular to the rotational axis, and the joining device is moved by a moving device such that the receiving tool is disposed at the restriction portion. Accordingly, the rotational runout of the rotating tool can be restrained effectively with a simple structure of a properly small-sized rotating tool and receiving tool.

Abstract: A friction stir welding (FSW) apparatus has an FSW tool adapted for joining work pieces supportable against a backing anvil. The FSW apparatus comprises a pair of clamping rollers maintained in substantially perpendicular relationship to the backing anvil as the FSW tool moves along the tool path. A roller pivot joint of the FSW apparatus maintains a cylindrical roller outer surface of each clamping roller in substantially parallel relationship to the top sides of the work pieces. The roller pivot joint may include a gimballing roller bearing to which the clamping roller is mounted. The roller bearing is universally movable in a variety of directions to maintain the perpendicular relationship of the clamping rollers relative to the backing anvil.

Abstract: Friction plug welding methods and systems plug a hole extending through a component part from front and back faces thereof. A sacrificial plate having an opening therethrough may be positioned against the back face of the component part with assistance from a restraint part (which is also preferably provided with a space of sufficient dept to receive a terminal end of the male plug) so that the opening is coaxially aligned with the hole to be plugged. Upon advancing a male plug of a plug rod into the hole under friction plug welding conditions, a friction weld region will therefore be formed between the male plug and defining surfaces of both the hole extending through the component part and the opening extending through the sacrificial plate. The plug rod may include an annular shoulder flange which defines a plane parallel to the front face of the component part so that flash flow from the friction welding will be displaced laterally of the hole. The male plug may be frustroconically shaped.

Abstract: A clinching method includes establishing a first layer on a second layer. The first layer has an aperture formed therein and is thinner than the second layer. A rotating punch is engaged with the second layer through the aperture in the first layer, thereby generating frictional heat and softening the second layer. The rotating punch is configured with at least a first diameter, a shoulder, and a second diameter that is larger than the first diameter. The rotating punch is pressed into the softened second layer, thereby causing at least some of the second layer to: back extrude through an annulus defined by the aperture in the first layer and at least one of the diameters of the punch; contact the shoulder of the rotating punch; and extend onto a surface of the first layer adjacent the aperture.

Abstract: A friction stir welding tool and weld metal structure with plural onion rings, in which the tool is formed on the tool head with three surfaces, which are connected to one another through three spaced surfaces. An eccentrical axis of the tool head deviates from a central axis of the tool handle. One of the three surfaces is a deviation cutting surface which is a flat surface formed by cutting off a wall thickness from one side of an outer peripheral surface of the tool head toward the central axis of the tool handle. Each of the three spaced surfaces is alternately formed with plural notches and plural protrusions. The above welding tool is used to perform a stir friction welding operation to two metals to form the weld metal structure with the same number of onion rings as the protrusions and notches of each of the spaced surfaces.

Abstract: A gimbaled-shoulder friction stir welding tool includes a pin and first and second annular shoulders coupled to the pin. At least one of the annular shoulders is coupled to the pin for gimbaled motion with respect thereto as the tool is rotated by a friction stir welding apparatus.

Abstract: Friction stirred welding equipment, developed according to requirements of high reliability, robustness, precision and low cost, weld lap and butt joints in complex surfaces with fixed pin tool under controlled downforce. Exemplary equipment comprises a control force orbital spindle, wherein a coaxial sensor measures the downforce and simultaneously the axial electrical actuator corrects axial tool position along the welding, by a direct axial force system control, in order to maintain controlled downforce according to previously set parameters. The equipment sets up, monitors and controls the spindle rotation speed, welding speed, acceleration speed and downforce and can record in a database the downforce and tool welding position during the welding.

Abstract: An apparatus for friction stir welding is described that includes a stationary assembly having a bore therethrough, the bore having an inner diameter, and a rotational assembly having a welding end. At least the welding end of the rotational assembly extends through the bore. A portion of the rotational assembly is adjacent the inner diameter of the bore. At least one of the adjacent portion of the rotational assembly and the inner diameter of the stationary assembly are configured such that rotation of the rotational assembly will cause plasticized material from a welding process that has entered an area between the adjacent portion and the inner diameter to move towards a welding zone located proximate the welding end.

Abstract: The invention is a welding tool used in a friction-stir welding apparatus for welding a plurality of members to be welded. The welding tool includes: a tool holder having a front end and a base end, the base end being held by the friction-stir welding apparatus so as to be driven to rotate and move by the friction-stir welding apparatus; and a welding unit of a wear resistant material adapted to be removably mounted on the front end of the tool holder, the welding unit mounted on the front end of the tool holder being immersed into a part of the members to be welded during a friction-stir welding.

Abstract: This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding.

Abstract: In the friction stir joining apparatus of the present invention, a rotation control unit variably controls a rotational speed of a rotor; and a straight movement control unit controls a straight movement of the rotor so as to control a pressure applied by the rotor to the object. The tip portion of the rotating rotor is pressed against a workpiece, thus spot joining is executed. The apparatus can execute frictional stirring joining without practical trouble under simple control.

Abstract: An apparatus for induction friction solid state welding a body having a work piece receiving bore. A stationary chuck is provided for securing a first tubular workpiece in the bore. A moving chuck is provided for securing a second tubular workpiece in bore. An induction heating coil is movable between an operative position and a stored position. An expandable cylinder moves the moving chuck toward and away from the stationary chuck. A torque transmission collar is used to rotate the moving chuck.

Abstract: A tool is provided that is capable of friction stir processing, friction stir mixing, and friction stir welding of high melting temperature and low melting temperature materials, wherein the collar is now divided into at least an inner and an outer collar coupled to the shank and the FSW tip, wherein new thermal barriers enable expansion of the inner collar to be directed inward to thereby create compression on the FSW tip instead of allowing the FSW tip to become loose in the tool at elevated temperatures.

Abstract: A probe for friction stir welding MMCs, ferrous alloys, non-ferrous alloys, and superalloys, as well as non-ferrous alloys, the probe including a shank, a shoulder, and a pin disposed through the shoulder and into the shank, wherein the pin and the shoulder at least include a coating comprised of a superabrasive material, the pin and shoulder being designed to reduce stress risers, disposing a collar around a portion of the shoulder and the shank to thereby prevent movement of the shoulder relative to the shank, and incorporating thermal management by providing a thermal flow barrier between the shoulder and the shank, and between the collar and the tool.

Abstract: A friction stirring-welding method capable of increasing the welding strength of a lap joint. A welding tool (1) comprises a small diameter projected part (2) at the tip of a shoulder (3). The welding tool is press-fitted to the upper plate (4) of the lap joint while being rotated. By a friction stirring action, an upper plate side welding boundary surface (6) plastically flows, a surface oxidation film on a lapped surface is peeled off, and the boundary surface is activated to provide an excellent welding part. Also, since the welding tool is formed in a shape having the small diameter semispherical projected part (2) at the tip thereof, the thickness (12) of an upper plate welding part is increased, and a lap joint part with high welding strength can be provided.

Abstract: A rotary tool for friction stir spot welding including: a rod-like probe to be inserted into one side of stacked planar portions of plural metal members to be joined while being rotated; and a cylindrical shoulder member which is disposed coaxially outwardly of the probe and which has a shoulder surface to be abutted against the one side of the stacked portions while being rotated, wherein the probe and the shoulder member are individual components and are disposed so as to have a double-acting structure which enable them to move independently in their axial direction, and in which a gap between an inner surface of the shoulder member and an outer surface of the probe is formed to have a small gap on a tip side of the rotary tool and to have an enlarged gap having larger clearance than the small gap on a base portion side thereof.

Abstract: A mandrel that provides a counter-force to the pressure exerted on the outside of a pipe or other arcuate surface by a friction stir welding tool, wherein the mandrel is expandable through the use of a wedge, and wherein the mandrel enables multiple friction stir welding heads to simultaneously perform welding on the arcuate surface.

Abstract: An inertia friction welding process comprises: a) providing first and second work pieces to be welded together; b) imparting motion to the first work piece relative to the second work piece thereby imparting kinetic energy to the first work piece relative to the second work piece; c) applying a predetermined force to move one or both of the first and second work pieces towards the other to create an upset length in the work pieces; characterized by; d) measuring the rate of motion of the first work piece relative to the second work piece; e) determining a predicted final upset length from the said measured rate of relative motion and said forth; f) comparing the predicted final upset length with a desired final upset length; g) adjusting the aforesaid kinetic energy to achieve substantially the desired final upset length.

Abstract: A friction stir welding device operable to weld a joint formed between a first workpiece and a second workpiece. The friction stir welding device includes a clamping device coupled to a tool body of the welding device for movement with the tool body along the joint. The clamping device includes a first guide member and a second guide member. The first guide member includes a clamping face configured to engage the first workpiece and the second guide member includes a clamping face configured to engage the second workpiece. The clamping face of the first guide member is directly opposed to the clamping face of the second guide member to resist separation of the joint.

Abstract: A friction stir welding apparatus has a novel tool-in-tool construction where a friction stir welding pin tool extends through a center bore of a friction stir welding shoulder tool and is moveable axially and rotationally relative to the shoulder tool. The pin tool and shoulder tool both have their own dedicated tool holders and spindles that enable the tools to rotate and move axially relative to each other and enable easy replacement of each of the tools.

Abstract: A linear friction welding head apparatus for dual axis forging, the apparatus including three sets of orthogonal actuators for providing X-, Y-, and Z-planes of apparatus movement for providing Y-axis oscillation, a first forge load along a first forge axis, and a second forge load along a second forge axis. A method for dual axis forging for welding including providing a welding head for applying first and second forge loads along X- and Z-forge axes to weld at more than one interface. The forge loads may be applied at right angles to each other and have magnitudes corresponding to weld interface length.

Abstract: A problem of FSW spot-welding is that a bonding strength tends to be low, since an area of metallic bonding is limited to the neighborhood of a pin portion of the welding tool. In order to solve the problem, after a tool (1) is inserted into a member (4) to be welded, a rotation shaft of the welding tool is tilted around a predetermined point (13) as a fulcrum, and the tip portion of the welding tool (1) is swung to enlarge a plastic flow area caused by rotation of the tool. As a result, the welding strength can be increased.

Abstract: Friction stir welding (FSW) processes, systems and the resulting friction stir welded components are disclosed whereby first and second workpieces are welded to one another using a first workpiece having mutually orthogonal structural components and a junction region therebetween which defines a bearing surface of predetermined geometry. A shoulder of a FSW tool may be brought into bearing contact with the bearing surface so that a pin extending from the shoulder of the FSW tool may be advanced into and through the one structural component of the first workpiece at an angle relative thereto so as to thereby form a friction stir weld region between the first and second workpieces. Some preferred embodiments will provide a bearing surface which defines an arcuately concave geometry, in which case the shoulder of the FSW tool defines an arcuately convex geometry conformably mateable with the bearing surface.

Abstract: A friction stir welding system that enables clamping of a pipe to enable friction stir welding around the pipe OD, a movable mandrel that provides a counter-force to the pressure exerted on the outside of a pipe by a tool, and a system for providing friction stir welding and repair inside a nuclear vessel in an underwater environment.

Abstract: A linear friction welding head apparatus for dual axis forging, the apparatus including three sets of orthogonal actuators for providing X-, Y-, and Z-planes of apparatus movement for providing Y-axis oscillation, a first forge load along a first forge axis, and a second forge load along a second forge axis. A method for dual axis forging for welding including providing a welding head for applying first and second forge loads along X- and Z-forge axes to weld at more than one interface. The forge loads may be applied at right angles to each other and have magnitudes corresponding to weld interface length.

Abstract: An apparatus and method are provided for measuring loads on a rotating friction stir welding tool of a friction stir welding machine. The apparatus includes a frame that can be connected to the friction stir welding machine, and rollers rotatably connected to the frame are structured to contact and rotate with the friction stir welding tool. Each roller is adapted to adjust in a respective direction and communicate with a respective load cell so that the load cells detect a positional characteristic of the rollers and measure loads applied to the rotating friction stir welding tool during operation. The rollers can contact the rotating tool directly during operation of the machine, such as while the rotating tools is being moved through a workpiece to form a friction stir weld joint, to measure the loads on the tool in the direction of movement of the tool and a direction normal to the movement, i.e., the path and path normal directions.

Abstract: A rotational tool retaining member unit 37 is mounted at one end portion thereof to a FSW gun body 26. The rotational tool retaining member unit 37 is provided at the other end thereof with a fitting hole 61 and a plurality of mounting passages 60 which are formed on a peripheral surface thereof such that the mounting passages 60 open on the opposite side of the one end portion and are spaced apart from each other in the circumferential direction. A mounting member unit 38 has a plurality of pin members 67. The mounting member unit 38 is mounted to the rotational tool retaining member unit 37 in such a manner that the pin members 67 are moved from the openings to the tip end portions of the mounting passages 60 and fitted thereinto. A rotational tool 33 is inserted into the mounting member unit 38. The rotational tool 33 has one end portion thereof a tie-in portion which is fitted to the fitting hole of the retaining means.