A bonding device for joining together a first member (3), an intermediate member (4), and a second member (3) which are layered as a laminated assembly includes a probe (12, 41), an anvil (11, 11b, 11c, 11d), a shoulder member (13,13a, 61,64,68), a drive mechanism (14) configured to rotate the probe around the central axial line and move the probe toward and away from the second member along the central axial line, and an electric power supply (15) electrically connected to the anvil and the shoulder member to conduct electric current through the laminated assembly via the anvil and the shoulder member.

A bonding device for joining together a first member (3), an intermediate member (4), and a second member (3) which are layered as a laminated assembly includes a probe (12, 41), an anvil (11, 11b, 11c, 11d), a shoulder member (13,13a, 61,64,68), a drive mechanism (14) configured to rotate the probe around the central axial line and move the probe toward and away from the second member along the central axial line, and an electric power supply (15) electrically connected to the anvil and the shoulder member to conduct electric current through the laminated assembly via the anvil and the shoulder member.

A bonding device for joining together a first member (3), an intermediate member (4), and a second member (3) which are layered as a laminated assembly includes a probe (12, 41, 52), an anvil (11), a drive mechanism (14) configured to rotate the probe around the central axial line and move the probe toward and away from the second member along the central axial line, and an electric power supply (15) electrically connected to the anvil and the probe to conduct electric current through the laminated assembly via the anvil and the probe.

A bonding device for joining together a first member (3), an intermediate member (4), and a second member (3) which are layered as a laminated assembly includes a probe (12, 41, 52), an anvil (11), a drive mechanism (14) configured to rotate the probe around the central axial line and move the probe toward and away from the second member along the central axial line, and an electric power supply (15) electrically connected to the anvil and the probe to conduct electric current through the laminated assembly via the anvil and the probe.

A swing arm assembly is provided for a spot welding machine. The swing arm assembly can accommodate a tip dresser or a tip exchanger and can include a lift assembly that can translate the tip dresser from a first position to a second position along a lateral axis.

An apparatus for measuring alignment of a welding gun comprises a case comprising an interior space and an open side, a supporting member mounted to the interior space, an upper block comprising a first end fixed to the supporting member, formed with an upper tip insertion hole at a second end, hinge-engaged with an upper pin mounted to the case and configured to rotate when an upper tip is misaligned, an upper sensor unit mounted adjacent to the upper block to detect rotation of the upper block, a lower block having a first end fixed to the supporting member, formed with a lower tip insertion hole at a second end, hinge-engaged with a lower pin mounted to the case, and configured to rotate when a lower tip is misaligned, and a lower sensor unit mounted adjacent to the lower block configured to detect rotation of the lower block.

The method comprises applying a spot load to a joint part between a first metal material and a second metal material in a state where sites to form the joint part are superposed on each other. When a total thickness of the first metal material and the second metal material at the joint part before bonding is defined as T.sub.0 mm, the total thickness thereof after bonding is defined as T.sub.1 mm, and T.sub.0/T.sub.1=R is defined as a reduction ratio, the reduction ratio R is 1.4 or more.

A joined body includes: a thin plate including through holes; a first member including a proximal portion having a portion contacting the thin plate, and a protruding portion that protrudes in relation to a contact surface of the proximal portion and is inserted through the through hole; and a second member arranged oppositely to the proximal portion via the thin plate and made of a material that is same as that of the first member. The thin plate is made of a material having a specific gravity smaller than that of the material forming the first and the second members. The second member and an end portion of the protruding portion are connected to each other, by a part of the second member and a part of the end portion being melt-solidified, the end portion being at a side opposite to a side connected to the proximal portion.

A joined body includes: a thin plate including through holes; a first member including a proximal portion having a portion contacting the thin plate, and a protruding portion that protrudes in relation to a contact surface of the proximal portion and is inserted through the through hole; and a second member arranged oppositely to the proximal portion via the thin plate and made of a material that is same as that of the first member. The thin plate is made of a material having a specific gravity smaller than that of the material forming the first and the second members. The second member and an end portion of the protruding portion are connected to each other, by a part of the second member and a part of the end portion being melt-solidified, the end portion being at a side opposite to a side connected to the proximal portion.

A method of forming an assembly includes providing a metallic first workpiece having base and a first layer disposed on the base and adhering a second layer onto the first layer. One of the first and second layers is formed of a zinc-based material formed of at least a majority of zinc, and the other of the first and second layers is formed of a metallic alloying material having a melting point higher than the melting point of the zinc-based material. Preferably, the first layer is formed of the zinc-based material, and the second layer is formed of the metallic alloying material with the higher melting point. A metallic second workpiece is disposed in contact with the second layer. A welding operation is performed to join the first workpiece to the second workpiece. A welded assembly is also provided.