Welding is a technique to join metals. You require a gas welding machine to repair or use metals as part of your job. Welding enables you to shape metals to create various products and is the most convenient method to join metal pieces. PowerHouse PHAW200 IGBT 200A Arc Welding Machine Welding machines generate intense and localized heat by creating an electric arc between the part to be welded and an electrode. The high temperature of the arc allows the edges of the weld to melt and fuse with a filler metal. This filler metal can be in the form of a rod or wire, depending on the welding required.