Composite manhole covers are cheaper and have no recycling value, but their bearing capacity is limited. Cast iron manhole covers are now made of ductile iron, which is safe, anti-theft, and has a large bearing capacity, but the price is slightly higher. Those with a bearing capacity requirement of less than 30 tons can consider using composite ones, while those with a bearing capacity greater than 30 tons must use ductile iron ones. 
1. Appearance: The exterior of the composite manhole cover series is beautiful and clean. There are a variety of color options. The surface of the manhole cover can be colored and designed according to design requirements. The color of cast iron manhole covers is monotonous and not aesthetically pleasing. The main color is black.
2. Weight: The composite manhole cover series is lightweight, approximately one-third of the weight of cast iron and cement counterparts.
3. Toughness: The composite manhole cover series has good toughness and high strength. The cast iron manhole cover series is strong but lacks toughness and is prone to cracking.
4. Noise: The cover seat of the composite manhole cover series is tightly combined, with no wobbling, bouncing, etc. The cast iron manhole cover series is cast and the cover seat is not tightly combined. When vehicles are driving, it is prone to jumping, tilting, making noise, and shifting.
5. Maintenance: The composite manhole cover series is corrosion-resistant, lightweight, can be colored, has good sealing performance, is easy to identify and maintain daily, effectively reducing maintenance labor costs and renewal expenses. The cast iron manhole cover series is heavy, prone to rust and corrosion, is easily stolen, and increases the difficulty of maintenance and renewal costs.
6. Cost: The unit cost of the composite manhole cover series is lower than that of the cast iron manhole cover series. 
In simple terms, cast iron manhole covers have high strength and hardness, are not easily corroded, have strong impact resistance, have a high load-bearing capacity, and are mostly used on municipal roads. Their safety performance is relatively good and they can be installed in a wide range of areas. Composite manhole covers are made of resin and composite materials, have no recycling value, and have good automatic anti-theft performance. The bending strength and compressive toughness of composite manhole covers are good, but their load-bearing capacity is not as high as that of cast iron manhole covers.

Cast iron manhole cover

Composite resin manhole cover