The weight of manhole covers varies depending on factors such as material, size, thickness, and purpose. The following are the weights of common manhole covers:

Classification by material

• Cast iron manhole covers: DN300-400mm manhole covers weigh about 50-70kg; DN500-600mm about 80-120kg; DN700-800mm about 150-200kg; DN900-1000mm generally 250-300kg.
• Steel manhole covers: DN300-400mm weighs about 30-50kg; DN500-600mm about 60-80kg; DN700-800mm about 100-150kg; DN900-1000mm generally 200-250kg.
• Composite manhole cover: DN300-400mm weighs about 20-30kg; DN500-600mm weighs about 40-60kg; DN700-800mm weighs 80-100kg; DN900-1000mm weighs generally 150-200kg.
• Cement manhole cover: DN300-400mm weighs about 30-50kg; DN500-600mm weighs about 60-80kg; DN700-800mm weighs 100-150kg; DN900-1000mm weighs generally 200-250kg.
• Fiberglass manhole cover: DN300-400mm weighs about 20-30kg; DN500-600mm weighs about 40-60kg; DN700-800mm weighs 80-100kg; DN900-1000mm weighs generally 150-200kg.

Classification by use

• Light manhole cover: used for sidewalks and non-motorized vehicle lanes, with a design weight of usually 10-25 kg.
  Medium manhole cover: suitable for general roads, bearing the load of motor vehicles, with a design weight of generally 25-50 kg.
• Heavy manhole cover: used in heavy-load areas such as highways, bridges, and airports, with a design weight of generally more than 50 kg.