Original plumbing trade vintage catalog for NATIONAL TUBE COMPANY, was located in Pittsburgh, PA. (United States US Steel Corporation Subsidiary). Manufacturers of Scale-Free Copper-Steel Pipe for Modern Building Service. Products shown include In Butt-Weld, Lap-Weld, Electric-Weld, Hammer-Weld and Seamless. Unbound from a large 1938 architectural catalog, this unique old four page technical specifications brochure would display beautifully matted and framed. A fantastic addition to your retro plumbing collection.