Pipes of metal, in particular steel pipes; pipelines of metal, in particular of steel; steel penstocks for the transport of oil and/or natural gas; pipe connectors of metal such as steel, in particular for oil pipelines or natural gas pipelines; threaded connectors of metal such as steel, in particular for oil pipelines or natural gas pipelines; pipe sleeves of metal, in particular of steel; threaded tubes of metal, in particular of steel; manifolds of metal for pipelines; pipe strings of met...