Pipes of metal, steel pipes, pipelines of metal, especially of steel, pressure pipelines of steel for the transport of oil and/or natural gas, pipe connecting pieces of metal, especially for oil pipelines or natural gas pipelines, gas tight threaded connecting pieces of metal, especially for oil pipelines or natural gas pipelines, pipe collars of metal, especially of steel, threaded pipes of metal, especially of steel, intersections of metal for pipelines, piping runs of metal, namely, metal ...