Embodiments of the present invention include a plasma cutting torch and plasma cutting torch components, such as electrodes, cathodes, retainer caps, etc. having a unique physical features, including threads relationships. Embodiments include torch components having modified square thread with a specialized thread configuration including a particular relationship between thread crest and root, and included angles of thread sidewalls.

A method of joining a first metal and a second metal is described. The first metal comprises Pb in an amount of at least 50 wt. % by weight of the first metal. The method comprises fusing the first metal and the second metal using non-consumable electrode arc welding.

There is provided a welded structure that can reduce fractures at welded portions. The welded structure includes two or three steel sheets and a lapped portion in which the steel sheets are overlapped and joined by spot welding at a plurality of locations, the welded structure including a spot weld portion, and, when a diameter of a nugget is d.sub.ng (mm), a tip diameter of an electrode used by the spot welding is d (mm), and an average thickness per steel sheet of the steel sheets at the lapped portion is t.sub.ave (mm), the spot weld portion satisfies d.sub.ng>d(t.sub.ave).sup.1/2 when 0.5 mmt.sub.ave<1.1 mm and d.sub.ng>1.05d when 1.1 mmt.sub.ave2.6 mm, in accordance with the average thickness t.sub.ave (mm).

The present disclosure provides a system for printing a three-dimensional object. The system may comprise a support for holding a portion of the object and a wire(s) source configured to hold a wire(s) of substantially the same or different diameters. The system may also comprise a print head. The print head may comprise a guide for directing the wire to the support. The system may also comprise a driver roller comprising a groove configured to contact a portion of the wire and direct the wire to the guide, and a power source in electrical communication with the wire and the support. The system may also comprise a controller configured to direct the power source to supply electrical current to the wire and the support. The electrical current may be sufficient to melt the wire when the wire is in contact with the support or the portion of the object.

The present disclosure provides a system for printing a three-dimensional object. The system may comprise a support for holding a portion of the object and a wire(s) source configured to hold a wire(s) of substantially the same or different diameters. The system may also comprise a print head. The print head may comprise a guide for directing the wire to the support. The system may also comprise a driver roller comprising a groove configured to contact a portion of the wire and direct the wire to the guide, and a power source in electrical communication with the wire and the support. The system may also comprise a controller configured to direct the power source to supply electrical current to the wire and the support. The electrical current may be sufficient to melt the wire when the wire is in contact with the support or the portion of the object.

A hybrid electrode for resistance spot welding and a method of resistance welding are provided. The hybrid electrode comprises a pin and a collar member. The pin comprises an electrically conductive material and a pin contact surface. The collar member comprises a material that is at least one of less electrically conductive than the electrically conductive material of the pin and less thermally conductive than the electrically conductive material of the pin. The collar member comprises a collar member contact surface, and defines an inner cavity and a longitudinal axis. The pin is at least partially disposed in the inner cavity and the pin contact surface extends away from the collar member and is offset a distance along the longitudinal axis from the collar member contact surface.

An electrode tip for resistance spot welding includes a main body with tip and base portions. The tip portion has a bottomed and substantially cylindrical shape. The base portion has a substantially cylindrical shape and merges into the tip portion. The main body is made of a copper alloy such as chromium copper. The tip portion has a bottom part and a barrel part. The bottom part has a pressure-contact surface that is not recessed with respect to a workpiece to be pressed. The barrel part has a substantially cylindrical shape and merges into the bottom part. The electrode tip may have an inner diameter ratio (inner diameter of the barrel part to an outer diameter of the base portion) of 0.4 to 0.6, and may also have a bottom thickness ratio (thickness of the bottom part to the outer diameter of the base portion) of 0.15 to 0.5.

The present disclosure provides a system for printing a three-dimensional object. The system may comprise a support for holding a portion of the object and a wire(s) source configured to hold a wire(s) of substantially the same or different diameters. The system may also comprise a print head. The print head may comprise a guide for directing the wire to the support. The system may also comprise a driver roller comprising a groove configured to contact a portion of the wire and direct the wire to the guide, and a power source in electrical communication with the wire and the support. The system may also comprise a controller configured to direct the power source to supply electrical current to the wire and the support. The electrical current may be sufficient to melt the wire when the wire is in contact with the support or the portion of the object.

The present disclosure provides a system for printing a three-dimensional object. The system may comprise a support for holding a portion of the object and a wire(s) source configured to hold a wire(s) of substantially the same or different diameters. The system may also comprise a print head. The print head may comprise a guide for directing the wire to the support. The system may also comprise a driver roller comprising a groove configured to contact a portion of the wire and direct the wire to the guide, and a power source in electrical communication with the wire and the support. The system may also comprise a controller configured to direct the power source to supply electrical current to the wire and the support. The electrical current may be sufficient to melt the wire when the wire is in contact with the support or the portion of the object.

A method of making a heat exchanger that includes providing a plurality of tubes. Each of the plurality of tubes has exterior cladding on an exterior surface, interior cladding on an interior surface, and a weld seam extending along the length of the plurality of tubes. The method further includes arranging the plurality of tubes such that each of the plurality of tubes is inserted into a corresponding header slot with the weld seams of each of the plurality of tubes oriented downward with respect to gravity, and brazing each of the plurality of tubes and the header after each tube has been inserted into a corresponding header slot. The brazing causes the interior cladding to melt and pool inside the plurality of tubes and along an interior side of the weld seams to form a clad cover portion encases debris generated while forming the weld seams.