C-Section Channels Explained: Uses, Sizes & Buying Tips

If you’re building a new home, planning an extension, or undertaking a DIY renovation, you’ll most likely need structural steel products. The C-section channel, also known as parallel flange channel (PFC), is one of the most versatile and widely used structural steel profiles.

From supporting brick walls to acting as the backbone of roof structures, these C-shaped steel beams do a lot of heavy lifting in Australian construction.

In this article, we unpack everything you need to know about C-section channels, from what they are and where they’re used, to understanding sizing and specifications, so you can buy them with confidence.

"The C-section channel is one of the most versatile and widely used structural steel profiles in Australian construction."

What is a C-section channel?

A C-section channel is a common type of structural steel profile shaped like the letter “C” when viewed in cross-section. It features a vertical web and two horizontal flanges (or protruded ridges at top and bottom), making it ideal for structural applications where a flat back and open face are needed.

Unlike universal beams (which have flanges on both sides), C-section channels have a flat surface that makes them easy to mount against walls, concrete, or other framing materials.

"Whether you're building a carport, a pergola or supporting structural loads, our C-section channels come in a variety of sizes and finishes to suit your needs."

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Common Uses of C Section Channels

C-section channels are widely used in construction applications because of their strength, versatility, and ease of use. Here’s where you’ll often see them used:

Wall and frame bracing: C-sections are often used in stud and purlin framing systems, especially for steel-framed homes, garages, sheds, and industrial buildings. They are favoured for their strength-to-weight ratio, which means they are lightweight but strong enough to support roof and wall loads. The flat face on one side makes it ideal to have a face finish on the outside of your building.

Lintels Over Doors and Windows: Structural steel C-section channels are an excellent choice for supporting weight above wall openings, such as doors and windows. Lintel beams will need special consideration to ensure you comply with the National Construction Code, which has recently been updated.

Carports, Pergolas, and Outdoor Structures: Because of their clean, minimal profile, C-section channels are frequently used for outdoor framing, such as carports, garden structures, or decking frames—especially when they are hot-dip galvanised for extra corrosion resistance.

Floor Joists and Bearers: C-section channels are also used as joists or bearers in steel-framed flooring systems, especially when timber isn’t a suitable option, such as areas with high moisture, where there is a termite risk, and in high bushfire risk areas.

"Hot-dip galvanised steel is a great defence against corrosion. It's perfect for outdoor and coastal construction projects."

Understanding Sizes & Specifications

When selecting a C-section channel, it’s crucial to understand industry sizing and specifications.

In Australia, most PFC sizing and specifications will use the depth of section (vertical web).

For example, a typical designation might look like: 150PFC.

This means:

150 mm = Depth of the section (vertical web)

75 mm = Width of the flange (horizontal top and bottom edges)

17.7 kg/m = Mass per metre of length

C-section channels are typically available in a range of depths (from 75 mm to 380 mm) and flange widths. The larger the depth, the heavier the weight the higher load-bearing requirements.

At Edcon Steel, we carry a full range of standard PFC sizes in stock and can cut them to your required length for fast, easy installation. All PFCs supplied by Edcon Steel are manufactured to Australian Standards, available in standard sizes with cut-to-length options, and are suitable for welding, drilling, and post-fabrication modification.

"At Edcon Steel, we don’t just supply steel, we cut it, drill it, and help you choose the right product for your build. Ask us how"

Buying Tips for Builders, Tradies & DIYers

If you are planning a project that requires C-section channels, you must consider several factors before placing an order.

Firstly, make sure you know your load requirements. Is your channel bearing a heavy structural load (like a lintel) or acting as a lightweight support frame (like a pergola roof)? This affects the depth, weight, and steel grade you’ll need. Speak with an engineer or builder if you’re unsure.

Secondly, the environment and exposure to the elements will drastically affect your choice. If your project is outdoor or coastal, you’ll need hot dip galvanised steel. If your structural steel will be visible, whether in an exposed roof structure or pergola, make sure you consider how you would like to finish or paint it. If you do, this will affect your product choice and surface preparation techniques.

Edcon Steel offer full lengths at economical pricing so look at your total length and see if it will work into a full length and save some money on your PFC purchases.
If you need your steel cut to size or drilled with fixing holes, Edcon Steel can fabricate to your specifications—just chat with someone from our team.

"From DIYers to professional builders, we make buying structural steel online simple, with expert support and statewide delivery."

Buy C-section channel online from Edcon Steel

At Edcon Steel, we pride ourselves on the expertise of our staff, our level of customer service and the depth of our local market knowledge. You can visit our stores to browse the range or pick up an online order.

Our staff are on hand to answer any questions you have about our full range of products and services, so feel free to contact us for your steel or metal solution today.

Frequently Asked Questions (FAQs)

What is a C-section channel?

A C-section channel (or PFC—Parallel Flange Channel) is a structural steel profile shaped like the letter "C", with a flat back and two flanges on the top and bottom. It’s widely used in structural framing, bracing, and load-bearing applications where a clean, mountable surface is required.

Where are C-section channels commonly used?

C-section channels are used in wall bracing, floor joists, lintels above doors and windows, pergolas, decks, carports, and steel-framed buildings. Their shape and strength-to-weight ratio make them ideal for a wide variety of structural applications.

What sizes do C-section channels come in?

PFCs are typically measured by depth × flange width × mass per metre (e.g., PFC 150 x 75 x 18). At Edcon Steel, we stock a full range from 75 mm to 250 mm depths (larger sizes are available with short lead times) and can cut to your required length.

Should I choose galvanised or black steel C-channels?

For outdoor or high-moisture environments, hot-dip galvanised (HDG) steel is recommended for its corrosion resistance. Black steel is more suited to indoor or protected environments, or where painting or powder-coating is planned.

Can Edcon Steel cut and fabricate C-section channels to size?

Yes. We offer custom cutting, drilling and fabrication services to suit your specs. Just provide your measurements, and our team will prepare your steel for fast, accurate installation.