800B125 and so on. Cast iron manhole cover specifications: heavy-duty 400, general 250, light 125, different sizes. 700MM. If less than this specification, there is a type of well called a manhole, 400*700B250.

Significantly enhanced the mechanical properties of ductile iron castings. The 800MM size is quite common, used for placing manhole covers. What are the specifications and sizes of ductile iron manhole covers and their supports?