This Architectural Drawing is AutoCAD 2d drawwing of Detail drawing of of steel pipe in AutoCAD, dwg file. Steel tubing can be made from various raw materials, like iron, carbon, manganese, vanadium, and zirconium. Like pipe, tubing can be produced as either seamless or welded. Seamless tubing is a solid block of steel that is rolled into a round shape and then pierced and stretched into its final length.