A structural fitter is a metal worker who produces building materials for construction projects, such as for tall buildings and container ships. Your duties and responsibilities include the layout and assembly of parts that make up a structure, and you may weld pieces or use other tools, such as jack bars, turnbuckles, pry bars, hammers, or grinders to ensure that the materials align perfectly. Sometimes you move the parts manually while for larger jobs you use cranes or other equipment to move pieces into place.