... gas for welding, welding argon gas of purity 99.9%, 99.99% and 99.999% Industrial grade welding pure argon gas, 99.99% purity argon gas/industrial gas/welding gas,argon gas for ... oxygen ≥99.5GB-T3863-1995CylinderSteel cutting, welding, flame processingIndustrial nitrogen ≥99.5GB-T3864-1996CylinderReplacement gas and protection gas for chemical industry, metallurgy, and electric ...