The D700 refers to the diameter of the manhole cover. In the north, it's generally 75-95. Additional Information: Ductile iron manhole covers are typically categorized into round and square sizes. Specifications mainly include: 450*750D400, how much? In fact, due to weather conditions, they are made heavier in the north as of current usage.

750B1C250700*800B125, etc. However, there are also some around 550MM in size, which are also widely used. In fact, there are many different sizes for manhole covers.

The load capacity can be achieved. The usage rate is also high. Many are in use. 800MM sizes are quite common, generally circular, with 500*600B125 cast iron manhole covers. In the south, lighter weights are used, such as 400*700C125400.