... , opens conveniently.5, saving investment: long-span, heavy-load, than iron low price and save pilferage or crush replacement costs.6 ... , high strength: strength and toughness is far higher than cast iron, and can be used in the wharf, airports, big span ... hot-dip zinc processed beautiful and durable, anti-corrosion, with iron plate not similar advantages.By hook or by hinge connecting linking ...