Standard structural C channel sizes for aluminum range from 2.00 × 1.00 up to 15.00 × 3.72 inches, with matched web thickness, flange dimensions, and weight per foot.
Aluminum C channel sizes follow standardized dimensions defined by ASTM and AISC structural shape tables, giving engineers and fabricators reliable profiles for framing, machinery, and support structures. Whether you need a light-duty rail or a heavy structural beam, the size system is straightforward once you know what the numbers mean.
What Are the Standard Aluminum C Channel Sizes?
The AISC/ASTM structural aluminum channel table lists profiles by depth × flange width, each paired with a specific web thickness, flange thickness, and weight per foot. The table covers sizes from a compact 2.00 × 1.00 profile up to a substantial 15.00 × 3.72 channel. Engineers Edge’s structural aluminum channel reference provides the full dimensional data for these profiles.
| Size (Depth × Flange Width) | Web Thickness (in) | Weight per Foot (lb/ft) |
|---|---|---|
| 2.00 × 1.00 | 0.130 | 0.580 |
| 3.00 × 1.41 | 0.170 | 1.420 |
| 6.00 × 2.03 | 0.314 | 3.630 |
| 15.00 × 3.72 | 0.716 | 17.280 |
Beyond these structural profiles, commercial aluminum C channels are commonly stocked from 1/2 × 1/4 inches up to 12 × 4 inches with various wall thicknesses for lighter-duty uses.
How Aluminum Channel Sizes Are Specified
Five key measurements define any extruded aluminum C channel: overall depth (height), flange width, web thickness, flange thickness, and the inside radius at the web-flange junction. The profile is an open-section shape with a flat web and two perpendicular flanges — that C-shape is what gives the channel its name and its structural efficiency.
To specify a channel correctly, list the alloy and temper first — 6063-T52 for architectural work or 6061-T6 when strength is critical. Then provide the dimensions, tolerances, surface finish, and cut length. Standard tolerances for extruded aluminum channel are ±0.25 mm on flange width for small to medium sizes and ±0.50 mm on overall height.
When inspecting delivered material, use calipers to confirm flange and web thickness, run a straightedge along the length to check for camber, and hold a square at both ends to detect twist.
Which Aluminum Channel Should You Choose?
The choice comes down to strength versus formability. For load-bearing frames, machinery bases, and structural supports, 6061-T6 aluminum channel offers minimum tensile strength of 38.0 ksi and yield strength of 35.0 ksi — numbers that match the ASTM structural aluminum channel spec. For architectural trim, railings, and cosmetic applications where surface finish matters more, 6063-T52 extrudes cleaner and resists corrosion slightly better.
Applications span architectural framing, solar panel mounting, transportation equipment, marine structures, and industrial machinery — anywhere the high strength-to-weight ratio and natural corrosion resistance of aluminum beat steel. The material is easy to cut, drill, and fasten, which keeps fabrication costs low.
Two mistakes trip up buyers: swapping flange width with overall depth, and assuming steel C-channel dimensions transfer directly to aluminum. Steel sizes follow different tables, and aluminum profiles use distinct wall thicknesses and inside radii that affect fit and load capacity. That inside radius matters especially if you’re using threaded inserts or bolted fasteners — a tight radius can force you to shim or ream holes. For a selection of vetted profiles, see our recommended aluminum C channel picks.
Before ordering, verify your load requirements, span, deflection limits, and environmental conditions. Structural capacity depends on alloy, temper, span, and loading layout — not just the outer dimensions.
FAQs
What does the first number in a channel size mean?
The first number is the overall depth of the web — the vertical leg of the C. A 6.00 × 2.03 channel has a 6-inch deep web, with 2.03-inch flanges and specific web and flange thicknesses matched to that profile.
Are steel and aluminum C channels interchangeable?
No. Steel C-channel dimensions follow different standard tables, and aluminum channels use distinct alloys, wall thicknesses, and inside radii. Even where outer dimensions match, load capacity and fastener fit will differ significantly between the two materials.
What alloy is best for structural aluminum channel?
6061-T6 is the standard choice for structural use, offering 35.0 ksi minimum yield strength and good corrosion resistance. For projects where appearance and formability matter more than raw strength, 6063-T52 is a better fit.
References & Sources
- Engineers Edge. “Structural Aluminum Channel — ASTM AISC Table.” Standard dimensional data for extruded aluminum C channel profiles.
- Metals Depot. “Aluminum Channel 6061.” Product specs and commercial size range for 6061-T6 extruded channel.
- Beamclamp. “C-Channel Dimensions.” Reference for channel sizing and tolerance information.