Design, manufacture, and sale of polymer organic and inorganic engineering plastic products and composite material products; design, processing, and sale of mechanical equipment and parts; riveting and welding processing; incoming material processing; mold processing and sale; sale of polytetrafluoroethylene raw materials, composite polytetrafluoroethylene auxiliary materials, composite polymer raw materials, railway rolling stock parts, railway special equipment and accessories, marine supporting equipment and parts, steel, and building materials; trade consulting services; operation of goods and technology import and export business.