... gas and illuminant gas puritystandardunitApplicationoxygen≥99.5GB-T3863-1995bottle/cylinder Steel cutting, ... industry, metallurgy, and electric industry.hydrogen≥99.9GB-T3634-1995bottle/cylinderChemical industry, glasses, ... Pure argon ≥99.99 GB/T4842-95Bottle Welding shielded welding, stainless steel smelting, container, steel structure manufacture, mold processing, etc. 99.999 ...