Steel calendering; Metallurgical special equipment manufacturing; Sales of mechanical and electrical equipment; Wire and cable business; Non-residential real estate leases; Fabrication of metal materials; Fabrication of metal structures; General equipment manufacturing (excluding special equipment manufacturing); Sales of metal materials; Metal structure sales; Sales of high-quality special steel materials; R&D of metal products; General machinery and equipment installation services; Research and development of new material technology; Technical services, technology development, technical consultation, technology exchange, technology transfer, technology promotion;