Steel is high in strength and lightweight; it has uniform material properties, stable mechanical properties, and good plasticity and toughness. Steel structures can be customized, prefabricated, and assembled on-site, allowing for rapid construction. They can accommodate large spaces and spans in buildings, and are easy to modify and dismantle. Main applications include: high-rise buildings, large-span stadiums, airports, train stations, gymnasiums, factories, warehouses, workshops, bridges, towers, equipment platforms, and prefabricated buildings. Advantages include: fast construction speed, easy to achieve large spaces and spans, good seismic performance, environmentally friendly and recyclable, less construction waste, high precision factory production, and lightweight construction that reduces foundation costs.