6 Construction materials made of metals, namely, [ liners, wires, pipes, soil anchors, soil nails, hooks, turnbuckles, sheet piling, plates, and ] cattle guards; construction elements made of metals, namely, [ liners, wires, pipes, soil anchors, soil nails, hooks, turnbuckles, sheet piling, plates, and ] cattle guards; pre-fabricated metal bridges and bridge components [ ; metal materials for earth wall and abutment systems, namely, wires, pipes, soil anchors, soil nails, hooks, turnbuckles, sheet piling, and plates ]