U.S. steelmakers and aluminum producers. Companies who have cut production and employees as a result of imports may now have reason to restart their production lines. Chicago-based Century Aluminum, whose products include the high-purity aluminum needed to make military fighter jets, shut down some production lines at its Hawesville, Ky., smelter in late 2015. CEO Michael Bless told Reuters last week that tariffs or import quotas would allow it to move back toward full production and rehire 350 workers at that facility. Its shares closed up 7.5 percent Thursday.