Iron or steel (excluding cast iron); tubes, pipes and hollow profiles (not seamless), n.e.c. in chapter 73

730611 Steel; stainless; line pipe of a kind used for oil or gas pipelines n.e.c. in chapter 73, welded, (not seamless) 730619 Iron or steel (excluding cast iron); line pipe of a kind used for oil or gas pipelines (other than of stainless steel or seamless), n.e.c. in chapter 73 730621 Steel, stainless; casing and tubing of a kind used in drilling for oil and gas, n.e.c. in chapter 73, welded, (not seamless) 730629 Iron or steel (excluding cast iron); casing and tubing of a kind used in drilling for oil and gas (other than stainless steel or seamless), n.e.c. in chapter 73 730630 Iron or non-alloy steel (excluding cast iron); tubes and pipes (not seamless), welded, of circular cross-section, n.e.c. in chapter 73 730640 Steel, stainless; tubes, pipes and hollow profiles, welded, of circular cross-section, n.e.c. in chapter 73 730650 Steel, alloy; tubes, pipes and hollow profiles (other than stainless steel or seamless), welded, of circular cross-section, n.e.c. in chapter 73 730661 Iron or steel (excluding cast iron); tubes, pipes and hollow profiles (not seamless), welded, of square or rectangular cross-section, n.e.c. in chapter 73 730669 Iron or steel (excluding cast iron); tubes, pipes and hollow profiles (not seamless), n.e.c. in chapter 73, welded, of non-circular cross-section (not square or rectangular cross-section) 730690 Iron or steel (excluding cast iron); tubes, pipes and hollow profiles (not seamless), n.e.c. in chapter 73