Enhanced the mechanical properties of ductile iron castings; 800mm sizes are quite common, used for placing manhole covers. What are the specifications and sizes of the ductile iron manhole covers and their supports?

400*600C250, standard manhole sizes, and change circular covers to this type, but the commonly used one is still the 600mm size. The company's product standards may vary according to the user, with heavy-duty 400, common 250, and light 125 square covers available (e.g., 500*500B125). The thickness of the covers varies depending on the material, usually between 75-95mm.