The weight of manhole covers varies significantly based on material, size, and load-bearing capacity. Here’s a detailed breakdown:

1. By Material

(1) Cast Iron (Most Common)

Gray Iron (HT):

• Light-duty: 50–80 kg (e.g., 600mm diameter, 10–15 ton capacity).
• Heavy-duty: 90–120 kg (e.g., 700mm diameter, 40+ ton capacity).

Ductile Iron (QT):

• Lighter than gray iron (10–20% reduction) with higher strength.

(2) Steel Fiber Concrete

• Weight: 80–150 kg (600–800mm diameter).
• Use: Cheaper but brittle, common for sidewalks.

(3) Composite (Resin/Fiberglass)

• Weight: 20–50 kg (600mm diameter).
• Pros: Lightweight, anti-theft, corrosion-resistant.

(4) Stainless Steel

• Weight: 60–100 kg (600mm diameter).
• Use: High-end areas (e.g., urban landscapes).

2. By Size & Load Class

Diameter (mm)	Cast Iron (kg)	Concrete (kg)
600	50–120	80–120
700	70–150	100–150
800	90–180	120–200

Load Classes:

• A15(Pedestrian): ~50–70 kg.
• B125(Road Traffic): ~100–150 kg.
• D400(Ports/Airports): 200+ kg.

3. Key Factors Affecting Weight

• Reinforcement: Steel bars in concrete increase weight.
• Thickness: Standard: 50–80mm; Heavy-duty: ≥100mm.
• Design: Lattice or solid designs alter weight.

4. Safety Notes

• Theft Risk: Cast iron covers are often stolen for scrap metal (hence composite alternatives).

Handling: Heavy covers (>80 kg) require machinery to lift.

 

For exact specs, check the cover’s label (e.g., “QT500-7 D400” means ductile iron, 40-ton capacity).

Need to buy? Suppliers include:

China: Hebei (cast iron), Jiangsu (composite).

Global: Check EN124 (Europe) or ASTM (USA) standards.

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