Fasteners, metal products, steel structure accessories, industrial and mining accessories, railway accessories, transportation facilities accessories, photovoltaic accessories, building accessories, bridge accessories, agricultural machinery accessories, auto parts, ship accessories, electric power fittings, hardware tools, stainless steel products manufacturing and sales; Sales of steel, building materials, lubricating oil, grease, automobile maintenance supplies, chemical products (excluding hazardous chemicals), valves, steel wire ropes, bearings, springs, labor insurance supplies, rubber products, plastic products, office supplies; Goods import and export business.