Sheet metal fabricating: metal roofing & trims Bronze ducts or ductwork, Zinc ducts or ductwork, Steel ducts or ductwork, Iron ducts or ductwork, Cement ducts or ductwork, Plastics duct or ductwork, Rubber duct or ductwork, Glass ducts or ductwork, Stone ducts or ductwork, Non ferrous alloy ducts or ductwork, Aluminum ducts or ductwork