Why Are Manhole Covers Round?

February 14, 2024

A round manhole cover won’t fall in no matter which way it is inserted into the hole, which is crucial for safety. If it was square, rectangular or oval, you could accidentally insert it at a diagonal, which would cause the manhole cover to fall in, which is dangerous for cars and pedestrians.

A circular manhole cover is also easier to move around because it can be rolled, which is less labor intensive than lifting and moving a heavy square one. Considering that the average manhole cover weighs 200 to 300 pounds, it is important to make sure your staff has a simple and efficient method of transporting them.

The last reason why most manhole covers are round is probably the most obvious, and it relates to safety again. The lip around the rim of the manhole supports the cover, which keeps it from falling in. If a rectangular or square cover was inserted into the manhole, it might fall through the opening itself, which is dangerous for cars and pedestrians who are not paying attention.

Another reason why manhole covers are usually round is because they are stronger than square ones. A circle has an equal distance from the center to every point on its edge, which makes it stronger against compression than a square cover with corners that aren’t as strong. The round shape also uses less material, which can reduce production costs in the long run.


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