UIG owns and operates production plants across the USA which supply both Nucor steel sites and third-party clients 24/7 with tonnage quantities of oxygen, nitrogen, and argon as well as exporting liquid cryogenic products by road tanker. Universal Industrial Gases, Inc. (UIG) is a wholly owned subsidiary of Nucor and a well-established, global engineer, constructor, supplier and operator of air separation plants and related equipment and services, based in Bethlehem, PA.