Businesses in the structural metal products category manufacture and supply metal components used to support or form part of buildings, infrastructure and industrial facilities. Products commonly include steel beams and columns, portal frames, roof trusses, bracing, connection plates, balconies, staircases, walkways, gantries and protective rails. Some firms also work with aluminium or other metals, depending on the application. Services may cover interpreting architectural or engineering drawings, preparing fabrication details, cutting, drilling, forming and welding metal, and applying protective finishes such as paint or galvanising. Fabricated items can be made to specified dimensions and supplied as individual components or assembled sections for a project. Some businesses also provide delivery, on-site erection, repair or alteration work, coordinating with builders, engineers and other contractors to ensure components fit the intended structure and installation.