What Are Steel Beams?

Mary McMahon
Mary McMahon

Steel beams are structural supports which are made from steel, an alloy of carbon and iron which is famous for its strength. Beams are critical to the support of a building, spreading the load of the building laterally to ensure that it is evenly distributed, so that the building will not be prone to buckling or sagging. Steel is a popular material for beams for a number of reasons, not least of which is that it is incredibly strong, and can therefore be used in structures which would otherwise be considered structurally unsafe.

Steel I-beam.
Steel I-beam.

Manufacturers produce steel beams in a number of standardized shapes and lengths for different applications. It is also possible to order steel beams which are fabricated to order, which may be necessary when a building is unusual in design. Special shipping is usually required for the beams, because they are large and heavy, which makes them challenging to transport.

Steel beams are manufactured in a number of shapes and lengths.
Steel beams are manufactured in a number of shapes and lengths.

When architects design a new building or make plans to renovate an existing one, they need to think about where beams are going to be placed, and what materials they are made from. These beams are standard in many types of construction for their strength, with designers choosing a placement which meets structural and aesthetic needs. Architects and engineers also need to make additional calculations which consider the total weight of the building, seismic activity in the region where the building is located, and the distribution of open space in the building, as all of these can influence structural integrity.

Steel beams are fabricated from steel sheets.
Steel beams are fabricated from steel sheets.

Some steel beams are fabricated by welding, with companies taking steel sheets and cutting and welding them to the desired shape and size. Hot steel can also be molded or run through an extruder to generate beams of a desired style. After a beam has been finished, it can be clad in various materials for fire resistance or camouflage. Fire resistance is a major concern for steel beams as they can warp or melt in temperatures which can easily be reached in a structural fire.

The manufacturing process for steel beams includes a process in which the beam is rated to determine the amount of weight it can safely bear. The load rating on a beam usually needs to exceed the needs of the building for safety, and building inspectors may require proof that the beams installed in a structure will meet the legal requirements for building safety.

Steel beams are commonly used for construction.
Steel beams are commonly used for construction.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


@umbra21 - It's easy to suspect other countries of skimping on construction and other costs. However, I'm sure they do have a national standard. If nothing else, than because they would want to be able to export steel beams to other countries, so not having a standard of safety would be shooting themselves in the foot.

On the other hand, there are always corrupt companies who will try to get away with not following the standards, but that isn't isolated to one particular country.

Whether or not the government is willing or able to enforce the rules is another matter.


They often use the steel industry as a sign of how the economy is doing. Steel is used to create infrastructure, like these steel beams. You basically can't build something new without them. For example in the United States, there were twice as many steel workers in the 50's as there were in the year 2000.

However, then you have to take into consideration that there are some up and coming countries that are furiously building new infrastructure, like China and India, and they have a huge demand for steel. So the steel industries in these countries is pumping.

It makes me wonder if they have the same standard of steel beams that they do in the US. I know they have regulated sizes in Europe and the US to make sure buildings conform to certain standards.


Do you know, I didn't realize what steel actually was until I read this article? I knew it was iron mixed with something else, but I thought it was a mixture of bronze and iron or something of that sort.

Although when I looked it up, apparently they do sometimes use other metals to mix with steel, like chromium and manganese.

Apparently cast iron is when they mix in more carbon, because it makes it less likely to melt.

The most interesting thing, I thought, was that high carbon steel seems to have been invented in Sri Lanka.

I guess I just associate steel with the idea of European blacksmiths, but they must have come late to the party. It was only in the last couple of hundred years that they started making steel more cheaply, and it could be used for things like steel beams.

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