A golf club head comprising at least one part manufactured via a metal injection molding process, and attached to another part of the golf club head via electrical resistance welding, is disclosed herein. The present invention is also directed to a method of making said golf club head, the method comprising the steps of providing a first golf club head part made from a first metal material, metal injection molding a second golf club head part from a second, different metal material, and electrical resistance welding the second golf club head part to the first golf club head part to form a combined part.

A welding apparatus for resistance-welding a tubular member and a bar member includes: a positioning jig configured to make contact with the bar member from one side of the bar member in a direction perpendicular to an extending direction of the bar member; a first power supply jig configured to press the bar member from the other side of the bar member in the direction; a second power supply jig provided on an anti-bar member side of the tubular member and configured to apply pressure to contact surfaces of the bar member and the tubular member; and means for supplying, with the bar member pressed between the positioning jig and the first power supply jig and the second power supply jig applying pressure to the contact surfaces, electric current to the first power supply jig, the bar member, the contact surfaces, the tubular member and the second power supply jig.

A method of manufacturing a terminal-formed electric wire includes a welding member placing process in which at least one welding member formed of metal having a melting point lower than that of a plurality of metal strands included in a core wire is arranged to the core wire of at least a terminal-forming target portion of the electric wire, and a terminal forming process in which the exposed terminal-forming target portion is interposed between first and second electrodes having a shape corresponding to a desired terminal shape, at least the welding member in the terminal-forming target portion is melted by electrically conducting the first and second electrodes while pressing the terminal-forming target portion with the first and second electrodes, and the melted metal is then solidified, so that the terminal-forming target portion is formed as a terminal portion having a desired terminal shape.

A golf club head comprising at least one part manufactured via a metal injection molding process, and attached to another part of the golf club head via electrical resistance welding, is disclosed herein. The present invention is also directed to a method of making said golf club head, the method comprising the steps of providing a first golf club head part made from a first metal material, metal injection molding a second golf club head part from a second, different metal material, and electrical resistance welding the second golf club head part to the first golf club head part to form a combined part.

A fuel cell includes a frame equipped membrane electrode assembly and a metal separator. The frame equipped membrane electrode assembly includes a membrane electrode assembly and a frame shaped insulating member connected to the membrane electrode assembly. The frame shaped insulating member is provided around the membrane electrode assembly. The metal separator includes a first bipolar plate and a second bipolar plate joined together, and the frame shaped insulating member includes a welding portion welded to the first bipolar plate by resistance welding.

A welded portion forming structure forms a welded portion that joins a valve seat and a cylinder head main body. If the distance in a radial direction between a vertex of a corner, which is formed by a first surface and a second surface of the convex portion, and the first origin portion is assumed to be A, and the distance in the radial direction between the vertex and the second origin portion is assumed to be B, then a relation that satisfies all of A>0, AB, and B0 holds. Moreover, an angle which a first joint surface of the valve seat forms with an axial direction and an angle which the second joint surface forms with the axial direction are equal.

A seam welding device sandwiches between a first roller electrode and a second roller electrode a laminate, which is formed by laminating a plurality of workpieces and disposing the thinnest workpiece, which has the smallest thickness among the workpieces, on the outside, to carry out seam welding. The second roller electrode, which is in contact with the thinnest workpiece, is disposed further along the direction of welding progress than the first roller electrode.