Abstract: A contact tip for arc welding includes a feed surface constructed of conductive material which has a negative thermoelectromotive force with respect to pure platinum at temperatures above 0.degree. C. When welding current flows from the contact tip to a welding wire, an endothermic reaction occurs at the feed surface to lower the temperature of the feed surface and to improve the thermal durability of the contact tip.

Abstract: In this method for removing spatter deposits accumulated upon the inner surface of the end portion of a tubular arc welding torch nozzle, an end portion of a welding rod being fed for arc welding through an end portion of this nozzle with a space being left between this welding rod and the inner surface of the end portion of the nozzle, an electrical current is supplied through an electromagnetic coil positioned longitudinally proximate to the end portion of the nozzle. This electrical current typically generates an electromagnetic force upon the spatter deposits in the general direction parallel to the central axis of the nozzle, thus removing such spatter deposits from the inner surface of the end portion of the nozzle.

Abstract: A welding structure for a disc wheel installed on a vehicle. The disc wheel comprises a rim and a disc, the disc having an outer peripheral portion fixed to an inner surface of the rim by welding. The edge surface of the outer peripheral portion of the disc is inclined with respect to the rim, and when assembled contains the end portion of the weld.