The Manhole cover is divided into six grades according to its carrying capacity on  the basis of GB/T23858-2009 "Checking manhole cover"rules
The first group: (minimum A15 type): green belts, sidewalks and other areas where motor vehicles are prohibited from entering.
The second group: (minimum B125 type): sidewalks, non-motorized roads, car parking lots and underground parking lots.
The third group: (minimum selection of C250 type): residential area, back alleys, only light motor vehicles or small cars driving, within 0.5m of curbs on both sides of the road.
The fourth group: (the lowest selection D400 type): urban trunk roads, highways, high-grade highways, highways and other areas.
The fifth group: (the lowest selection E600 type): freight station, dock, airport and other areas.
Group 6: (minimum F900 type): Airport runway and other areas.
Note:
The load capacity of manhole and the ability of manhole cover to pass through the vehicle is not a concept.

The manhole load capacity means that the pressure test is carried out by a pressure tester within a unit area, usually 40 tons. And if it is through the car, the 5-axis heavy-duty truck calculation formula: 5 axes x 40 tons = 200 tons. The heavy manhole cover is guaranteed to pass when the total weight of the car is 200T.