Hello saipen7000, helium is generally used as a shielding gas by itself or in combination with argon for use in welding aluminum with either the GTAW aluminum process or the GMAW aluminum process, might also apply to copper welding. It can also be used in conjunction with a couple of other gases for tri-mix use in the GMAW process for certain types of steel or stainless welding. Hope this answers your question. Best regards, aevald