The argon gas is used in welding arc welding,stainless steel amelting, container, steelstructure manufacture,mold prossing,ect Gas Name Chemical Formula Specification(%) Impurity (ppm) Argon Ar 99.99 O2≤10 THC≤10 N2≤50 H2≤5 H2O≤15 99.999 O2≤2 THC≤2 N2≤5 H2≤1 H2O≤4 99.9995 O2≤1 THC≤0.5 N2≤2 H2≤0.5 H2O≤1 Argon gas