Wide Flange Beam versus I-Beams: A Builders Guide

When it comes to building, the beam is the key to a long-lasting and beautiful structure. But there are many different types of beams out there. Today let’s look at two of the most common beams. These two also have quite a few similarities and differences that allow for different applications for structuring something stable

Each project is unique and comes with its own set of challenges, and that is why having options and knowing when to use a particular type of beam is critical. This short guide will go over what wide flange beams are and how they compare to I-beams. 

Some Key Terms about Beams

The construction world is littered with terms. Here are some specific terms that are used when talking about beams, both wide flange and I-beams. 

  • Flanges. This term refers to the horizontal pieces on a beam. Think of them as the bread to a sandwich. The flanges are there to help resist the bending of the beam.
  • Web. This term refers to the vertical piece that connects the two flanges. The web would be the meat and cheese. The web is the part of the beam that takes the brunt of the force that is placed on the beam. 

Wide flange beams and I-beams both come in a variety of section depths, weights, web thicknesses, flange weights, and other specifications, depending on how you plan to use them.

When ordering steel beams, it’s essential to understand what the size means. For example, a 10×20 beam would weigh 20 pounds per foot and a 10-inch depth. Different sizes are ideal for various projects, and builders have to take into account factors like:

  • Deflection. It’s important to choose the right thickness to minimize any deformation of the beam.
  • Vibration. Builders pick beams of specific masses and stiffness to prevent any vibrations in the building.
  • Bend. The strength of a beam’s cross-section must accommodate yield stress.
  • Buckling. The flange size is chosen to prevent local, sideways, or torsional buckling.
  • Tension. The web thickness of a beam has to be appropriate for the project so that it won’t ripple, buckle, or fail under tension.

What is a Wide Flange Beam?

The wide flange beam is a steel beam that features a shape that is similar to the letter H that is turned on its side. The length of the flange is the same length as the web. These beams can be made with varying grades of steel, including recycled steel. 

Commonly these are best used as temporary support construction. Such as support to hold background while building walls, bridges, or retention walls. When these beams are used as a foundation, they are typically part of a more significant construction project and are often used to stabilize structures. 

Related: A36 Steel Grade Guide and FAQ

What is an I-beam?

I-beams are made out of steel, aluminum, and other low alloy steel. While the I-beam looks very similar to a wide flange beam, the flange on these beams is tighter. The shorter flange to web ratio gives these beams the look of the letter I. 

The I-beam is a construction base material and has many different uses like building bridges, frames, and more. Their design is to allow the beam to bend under high load pressure instead of buckling. 

The I-beam is a standard beam that is used in steel construction. They are versatile and can hold up against stress. The shape of the I-beam does not require extra steel and makes them cost-effective. The I-beam is considered to be a universal beam in the construction world.

Do you need other types of metal for your construction project in Austin, Texas? Make South Austin Metals your one-stop-shop for everything you need.

Related: What is Gaulling and How to Fix it.


If you have ever been to a stockyard, you might not have even noticed the difference between the wide flange beam and the I-beam. And while both have their uses, some key differences can affect how and when you use them in construction projects.

Support beams


Some key features that set the two beams apart are that the I-beam has tapered flanges that help to stabilize the beam and make it lighter than its counterpart. Wide flange beams have a wider flange and web than an I-beam. That allows the wide flange beam or H beam to handle a more considerable amount of weight. However, that does make the wide flange beam heavier overall. 

Beams are often categorized into S or W shapes. Steel I-beams are considered to be in the S category, and that is why they are universal when it comes to long-span structural beams

Another key difference is the width of the web and flange. At the same time, wide flange beams have an almost equal width web and flange. I-beams have a much more narrow flange in comparison to their web. 

Key characteristics of wide flange beams include:

  • They are much heavier than I-beams, meaning they can typically take more force.
  • They have a thicker center web, often increasing their strength.
  • They can usually be built up, meaning that you can use them to build up to any height or size.
  • You can use them for spans of up to 330 feet.
  • They have top and bottom flanges, which stick out further from the web versus I-beams.
  • Wide flange beams look like a single piece of metal, but they have a bevel where the three pieces come together.

Key characteristics of I-beams include:

  • I-Beams are lighter, making them a better option for buildings where force and weight on a wall might pose structural issues.
  • They have thinner center webs, meaning they can’t take the same amount of force as a wide flange beam.
  • You can only build up I-beams to the size the manufacturer’s milling equipment allows.
  • I-beams can be used for spans of 33 to 100 feet.
  • Like wide flange beams, I-beams have top and bottom flanges, but they are not as wide and significantly shorter.
  • Unlike wide flange beams, I-beams are a single piece of metal. Riveting and welding are not involved in their creation.

These fundamental differences are what make both beams useful in various applications

Applications of steel I-beams

Here are some places that steel I-beams are commonly used rather than wide flange beams.

  • Support beams for the construction of buildings, facilities, and engineering.
  • Support beams for steel channels, steel angles, or bridges.
  • Workplace platforms.
  • Factories, shops, and warehouse construction.
  • Truck bed framing.

Applications for wide flange beams

Here are some practical applications for the use of wide flange beams.

  • Construction support beams for factories, shops, and steel buildings.
  • The support of factory platforms.
  • Bridges, both construction and support.
  • Frames for truck bed.
  • Machinery.

While you can see, there are some places these beams overlap. Both have practical uses in construction settings.

Related: Cold Welding 101


A common question is what beam is better, and that’s not quite the question that should be asked. Instead, it should be why the particular type of beam is best suited for my project. Engineering is critical when deciding what beam would work best and when to use them and how to mix the two types. 

Both the I-beam and the wide flange beam are capable of being dependable weight-bearing materials. Both materials are used for developing structures, and blueprints should clearly specify if one beam should be used over another. For more minor supports, there are lighter junior beams that you can use. 

Related: Cold Rolled vs. Hot Rolled Steel

Where to Buy Wide Flange and I-Beams

No matter which type of beam you choose for your next project, steel beam fabrication provides you with fast, affordable, and efficient materials for any building application. It takes experience, expert-level knowledge, and specialized tools and facilities to fabricate safe, strong, reliable steel—Don’t trust just any company with your wide flange and I-beam fabrication.

South Austin Metals can source materials, design, cut, and fabricate the steel you need for your project. We can even deliver it to your job site and help install it if needed! We’re your Austin, Tx metal supplier, fabricator, and welder turn-key solution. With decades of experience working on in-house custom fabrications, we’ve been helping local builders with their projects for over 50 years.

Get in touch with South Austin Metals for your metal fabrication and custom welding needs for your next project.


Both the wide flange and I-beam have their uses in construction, and there might be situations where both beams will work just fine. However, knowing the differences and what strengths you are looking for in your structure is key to ensuring the best material is used for the job. 

South Austin Metals is your go-to source for metal supplies, I-beams, and other construction materials you need. We believe in easy and affordable sales. Our sales experience allows you to get back to your project today.

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