If you're sourcing steel C channels for a structural project, you've probably noticed how many size variations there are. Picking the right section isn't just about depth — flange width, web thickness, and weight per foot all factor into load capacity, fabrication cost, and shipping weight. At Royal Steel Group, we supply AISC-standard structural steel channel from C3 through C15 to buyers across North America, Latin America, and beyond. This guide pulls together the dimensional data, weight specs, and structural properties you need to make a confident selection.
Quick Reference: Common C Channel Sizes
Here's a fast comparison of the sizes we ship most frequently. These are the workhorse sections you'll see in everyday structural fabrication, equipment supports, and trailer builds.
| Channel Size | Depth (in) | Weight (lb/ft) |
| C3 × 4.1 | 3 | 4.1 |
| C4 × 5.4 | 4 | 5.4 |
| C6 × 8.2 | 6 | 8.2 |
| C8 × 11.5 | 8 | 11.5 |
| C10 × 15.3 | 10 | 15.3 |
| C12 × 20.7 | 12 | 20.7 |
If you're still narrowing down options, the full chart below has every standard size with complete dimensional data.
Full AISC C Channel Dimensions Chart
All sections below follow AISC (American Institute of Steel Construction) standard specifications. We've included both imperial and metric units side by side for international projects.
| Designation | Depth (in) | Flange Width (in) | Web Thickness (in) | Weight (lb/ft) | Depth (mm) | Flange Width (mm) | Web Thickness (mm) | Weight (kg/m) |
| C3 × 4.1 | 3 | 1.41 | 0.17 | 4.1 | 76.2 | 35.8 | 4.3 | 6.1 |
| C4 × 5.4 | 4 | 1.58 | 0.18 | 5.4 | 101.6 | 40.1 | 4.6 | 8 |
| C5 × 6.7 | 5 | 1.75 | 0.19 | 6.7 | 127 | 44.5 | 4.8 | 10 |
| C6 × 8.2 | 6 | 1.92 | 0.2 | 8.2 | 152.4 | 48.8 | 5.1 | 12.2 |
| C7 × 9.8 | 7 | 2.09 | 0.21 | 9.8 | 177.8 | 53.1 | 5.3 | 14.6 |
| C8 × 11.5 | 8 | 2.26 | 0.22 | 11.5 | 203.2 | 57.4 | 5.6 | 17.1 |
| C9 × 13.4 | 9 | 2.43 | 0.23 | 13.4 | 228.6 | 61.7 | 5.8 | 19.9 |
| C10 × 15.3 | 10 | 2.6 | 0.24 | 15.3 | 254 | 66 | 6.1 | 22.8 |
| C12 × 20.7 | 12 | 2.94 | 0.28 | 20.7 | 304.8 | 74.7 | 7.1 | 30.8 |
| C15 × 33.9 | 15 | 3.4 | 0.4 | 33.9 | 381 | 86.4 | 10.2 | 50.4 |
At a glance, standard C channel sizes cover:
Depth: 3 in to 15 in (76.2 mm to 381 mm)
Flange width: 1.41 in to 3.40 in (35.8 mm to 86.4 mm)
Weight: 4.1 lb/ft to 33.9 lb/ft (6.1 kg/m to 50.4 kg/m)
C Channel Sizes in Metric
While the AISC designation system uses inches and pounds, many of our international clients — particularly in Europe, the Middle East, and Southeast Asia — work in millimeters and kilograms per meter. The chart above already includes both systems so you can cross-reference directly without doing the math yourself.
If you're working on a project that specifies metric channel sizes (like UPN or UPE sections), those are different profiles altogether. Reach out to our sales team and we'll help you find the closest equivalent or source the exact section you need.
Structural Properties for Engineering Calculations
For load-bearing applications, you'll need more than just dimensions. The table below lists the key section properties engineers use for bending and shear calculations.
| Designation | Area (in²) | Ix (in⁴) | Sx (in³) |
| C3 × 4.1 | 1.21 | 1.77 | 1.18 |
| C4 × 5.4 | 1.59 | 4.47 | 2.23 |
| C5 × 6.7 | 1.97 | 8.72 | 3.49 |
| C6 × 8.2 | 2.41 | 15.4 | 5.14 |
| C7 × 9.8 | 2.88 | 25.1 | 7.18 |
| C8 × 11.5 | 3.38 | 38.5 | 9.62 |
| C9 × 13.4 | 3.94 | 56.5 | 12.6 |
| C10 × 15.3 | 4.49 | 79.1 | 15.8 |
| C12 × 20.7 | 6.08 | 147 | 24.5 |
| C15 × 33.9 | 9.97 | 370 | 49.3 |
What these numbers mean:
Area (A)— The cross-sectional area of the channel. Useful for calculating total steel weight and axial load capacity.
Ix (Moment of Inertia)— A measure of the section's resistance to bending about the strong (x-x) axis. Higher values mean stiffer beams.
Sx (Section Modulus)— Derived from Ix, this is the value you plug into bending stress formulas (σ = M/S). It's the go-to parameter for sizing beams under flexural load.
If you're working on a specific load case and aren't sure which section to spec, send us your calculations — our technical team can double-check and recommend the most cost-effective size.
Understanding C Channel Dimensions
It helps to know what each dimension does when you're selecting a channel. Here's a quick breakdown:
Depth (d) — The vertical height of the channel. This is the number in the designation (C6 × 8.2 means roughly 6 inches deep). Depth is the biggest driver of bending strength — deeper channels handle more load across the same span.
Flange Width (bf) — The width of the top and bottom flanges. Wider flanges give you more surface area for connections and improve lateral stability.
Web Thickness (tw) — The thickness of the vertical web. Thicker webs mean higher shear strength and better resistance to local buckling.
Weight per foot (lb/ft) is also worth paying attention to — it's how you estimate total material cost and shipping weight for your order.
Example: A C6 × 8.2 channel has a nominal depth of 6 inches and weighs 8.2 pounds per foot. A 20-foot stick would weigh roughly 164 lbs. Step up to a C12 × 20.7, and that same 20-foot length comes in at about 414 lbs.
Common C Channel Sizes and Where They're Used
Not every size fits every job. Here's how the typical range breaks down by application:
Small channels (C3 – C5): Light-duty work
Equipment brackets and mounts
Machinery bases and guards
Light framing and trim
Small support structures
These are the lightweight sections — easy to cut and fabricate, but not meant for heavy loads.
Medium channels (C6 – C8): The sweet spot
Structural frames and purlins
Roof and wall supports
Trailer and truck body frames
Equipment platforms and stairs
This is where most of our orders fall. C6 and C8 channels strike a good balance between strength and weight, making them versatile for a wide range of commercial and industrial projects.
Large channels (C10 – C15): Heavy structural duty
Building columns and main frames
Industrial walkways and mezzanines
Heavy machinery supports
Structural reinforcement and bracing
When the load goes up, you go deeper. C12 and C15 channels handle serious bending loads and are common in industrial construction and infrastructure projects.
How to Pick the Right C Channel Size
There's no one-size-fits-all answer, but these are the factors that usually drive the decision:
1. Load requirements — Heavier loads need heavier sections. Start with your bending and shear calculations, then pick a section with enough Sx and web thickness.
2. Span length — Longer spans need deeper channels. If your beam is spanning 20 feet, a C6 probably won't cut it — you'll likely need C10 or larger.
3. Connection details — Wider flanges make bolting and welding easier. If you're connecting multiple members, consider flange width alongside depth.
4. Budget and weight — Heavier sections cost more per foot and add to shipping costs. Sometimes a slightly deeper, lighter channel gives you the strength you need at a lower total weight than a shorter, heavier one.
If you're working from a set of drawings, send them over and we'll quote the exact sizes you need. If you're still in the design phase, our team can help you value-engineer the section selection.
FAQ
1. What are the standard steel C channel sizes?
Standard AISC C channels range from C3 (3 inches deep) up to C15 (15 inches deep), with weight per foot increasing as you go up in size.
2. How do you read a C channel size like C8 × 11.5?
The first number is the nominal depth in inches, and the second is the weight per foot in pounds. So C8 × 11.5 means an 8-inch deep channel that weighs 11.5 lb/ft.
3. How much does C channel weigh per foot?
It depends on the size. On the light end, a C3 weighs about 4.1 lb/ft. At the heavy end, a C15 comes in at 33.9 lb/ft. The full chart above lists the weight for every standard size.
4. What are C channel dimensions in inches?
U.S. standard C channels are specified in inches — depth, flange width, and web thickness are all measured in inches, with weight expressed in pounds per foot.
5. Do you supply C channels in metric sizes?
We primarily stock AISC-standard (imperial) C channels, but we regularly supply metric conversions and can source metric channel sections (UPN, UPE, etc.) for international projects. Let us know what you need and we'll put together a quote.
Ready to Source C Channels for Your Project?
Royal Steel Group supplies AISC-standard steel C channels in all common sizes, with mill-direct pricing and international shipping to over 80 countries. Whether you need a single bundle or a full container load, we'll get you the right material at a competitive price.
[Request a Quote → ] or email our sales team at admin@royalsteelgroup.com with your size, quantity, and destination port. We typically respond within 24 hours.
Post time: Aug-10-2026