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All About Surface Box Covers – Material, Methods, & More

With the rise in metropolitans and smart cities, proper city planning remains the utmost concern. Significantly, the sewage management that runs below a city. Not just the cities, but the towns also need to have an impeccable sewage management system.

One of the essential parts of this sewage management system is the surface box covers. Surface box covers are installed on the surfaces or roads so that it easy to repair or inspect the subsurface utilities.

Let us through some light on the surface box covers, manufacturing process, materials, and quality checks.

Materials Used In Surface Box Covers

Surface box covers in India are usually made up of cast iron. Ductile cast iron is used for its enhanced strength and durability. Ductile cast iron contains manganese that helps to form nodules in the carbon present in the cast iron. Generally, this makes it more robust and malleable.

Gray cast iron is also used for surface box covers. It consists of the element iron and an alloy of silicon and carbon.

The other materials used to manufacture surface box covers are silica sand, clay, coal, and water.

Methods of Production

Surface box covers in India are manufactured in large foundries. The scrap steel that comes into the foundry is melted and alloyed to form an iron casting. The casting process usually consists of the following steps-

Pattern Design

Aluminium patterns are designed for the top of the surface box covers. It is also carved out of wood, but considering the mass production in large factories, aluminium is considered the most viable option.


To form the surface box cover, scrap steel is melted in a furnace with a temperature of around 1500⁰C. Now the alloy metals are added to the moulting metal to increase its strength. Flux is also added to remove the impurities from the molten iron.


Sand moulds are created for the upper and lower part of the surface box. Green sand is used for the moulds. Both the moulds are tightly packed, and molten iron is poured through the vent. The vent also allows the gases to pass through the vent.


It takes about a day for a surface box to cool down completely. It cools down sufficiently in 60-90 minutes to be removed from the mould. It is then cleaned with a wire brush to present a complete look.

Quality Control For Surface Box Covers

Raw materials like scrap iron are not controlled. But the molten metal undergoes quality checks to analyse and confirm the appropriate quantities of alloys and flux. Strength and ductility are also measured using a tensiometer.
Also, the manufacturing process emits gases like carbon monoxide, sulfur dioxide, and hydrogen sulfide. The quality control team checks the permissible limits of these gases to avoid any health or safety hazards.


Next time you walk across a street and see a surface box cover, you know how it’s made and what purpose it serves.
The quality of surface box covers differs from manufacturer to manufacturer. If you wish to know more about the quality, manufacturing, and purchase of surface box covers, we recommend you to visit