A welding torch includes an inner tube of a helically wound wire to define a passage for a welding wire, a conduit in which the inner tube is inserted, the conduit having a curved portion, a torch body including a tip portion and a nozzle, a torch holder having a gas supplying member that supplies a shield gas into a space between the inner tube and the conduit, a feed unit provided upstream of the torch holder to feed the welding wire forward to or backward from the inner tube, and a sealing mechanism for preventing a reverse flow of the shield gas to the feed unit. A gap is defined between the adjacent wires of the inner tube allowing the shield gas to flow therethrough, and permitting wear debris generated by abrasion of the welding wire sliding in the inner tube to be ejected out from the nozzle.

An apparatus and system for preheating and removing surface oxidation of welding wire using electric arcs one via three or more tungsten electrodes connected to a polyphaser preheating power source is disclosed. Electric arc preheating of welding wire allows increased efficiency and deposition rates.

A MIG welding torch adapter that attaches to and/or replaces a welding torch's nozzle and enables welding in confined spaces includes: (1) a wire guide, (2) a turning nozzle that is concentric with and encloses said wire guide, (4) a collar that detachably slip-fits onto a MIG welding torch's contact tip, (5) an attachment tube that attaches to the nozzle, (6) an entry guide wire adapter that directs the free end of the torch's electrode wire move into the wire guide, (7) an exit guide wire adapter that guides the electrode wire as it exits this adapter, and (8) entry and exit spacers that enable the torch's shielding gases to flow through this adapter.

An end assembly for use with a welding device having a chamber between the diffuser sleeve and the insert which allows for cooling the insert and for controlling the flow of gas through the end assembly. Some of the components of the end assembly such as the contact tip, insert and gooseneck are constructed of a conductive material which are securely held together in contact by a diffuser sleeve constructed of a dissimilar material. The end assembly provides better conductivity of the current through the end assembly for use of less energy during welding.

Method and device for marking a workpiece surface (2A) of a metal workpiece (2), in which a welding torch (3) comprising a welding wire electrode (4) is guided along the workpiece surface (2A) to be marked and meanwhile a wire end (4A) of the welding wire electrode (4) is moved towards and away from the work-piece surface (2A) to be marked, wherein an electric voltage (U) present at the welding wire electrode (4) and/or an electric current (I) flowing through the welding wire electrode (4) bring about electric sparks, which bring about material removal and/or material alteration at the workpiece surface (2A) of the metal workpiece (2) to mark the workpiece surface (2A).

A method of operating a welding torch using a rotating coupler assembly that operates between 0 and 800 amps. The rotating coupler assembly allows for 360 degrees of rotation while keeping rotational friction at a minimum. The breakaway torque for the rotating coupler assembly is insignificant and the rotating coupler assembly can be rotated with little effort by hand. While the rotating coupler assembly minimizes rotational friction the design allow for rotating coupler assembly to continue to operate after 1-5 mm of wear on the contact surfaces. An embodiment of the rotating coupler assembly can be quickly disconnected from the unicable.

In various embodiments, three-dimensional layered metallic parts are substantially free of gaps between successive layers, are substantially free of cracks, and have densities no less than 97% of the theoretical density of the metallic material.

In various embodiments, wire composed at least partially of arc-melted refractory metal material is utilized to fabricate three-dimensional parts by additive manufacturing.

A pair of two nozzle assembly receptacles for a dual-wire welding torch for two melting welding wires, has a torch body, a connection for a hose package, and a common gas nozzle, and a dual-wire welding torch has a pair of two nozzle assembly receptacles constructed as inserts for accommodating and fastening in interfaces in the torch body provided therefor, and the nozzle assembly receptacles respectively have an opening for the accommodation of a nozzle assembly in each case, which openings are arranged at an angle between 0° and 20° to one another, so that the central axes of the contact tubes or the welding wires running therein enclose this angle to one another.

In various embodiments, three-dimensional layered metallic parts are substantially free of gaps between successive layers, are substantially free of cracks, and have densities no less than 97% of the theoretical density of the metallic material.