C-Channels — American Standard Channel Chart
ASTM A6 / AISC Steel Construction Manual dimensions and section properties
American Standard channels are designated by exact depth and weight: a C10x15.3 is exactly 10 inches deep and weighs 15.3 pounds per foot. This chart covers all 29 standard sizes from C3x4.1 to C15x50, grouped by depth. Every size links to a full datasheet with metric conversions, bar weights, and a worked deflection example.
Channels put all their flange on one side of the web, which makes them ideal wherever a flat back matters — stair stringers, frames, rails, and bolted-up built-up sections. The taper on C-channel flanges (about 16.7%) is why the listed flange thickness is an average. For European projects, the closest metric relatives are the UPN channels — our UPN table lets you compare directly.
C3 series (C3x4.1 – C3x6)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C3x4.1 | 3 | 1.41 | 0.17 | 0.27 | 4.1 | 6.1 | 1.2 | 1.65 | 1.1 | 0.19 |
| C3x5 | 3 | 1.5 | 0.26 | 0.27 | 5 | 7.4 | 1.47 | 1.85 | 1.23 | 0.24 |
| C3x6 | 3 | 1.6 | 0.36 | 0.27 | 6 | 8.9 | 1.76 | 2.07 | 1.38 | 0.3 |
C4 series (C4x5.4 – C4x7.25)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C4x5.4 | 4 | 1.58 | 0.18 | 0.3 | 5.4 | 8 | 1.58 | 3.85 | 1.93 | 0.31 |
| C4x7.25 | 4 | 1.72 | 0.32 | 0.3 | 7.25 | 10.8 | 2.13 | 4.58 | 2.29 | 0.43 |
C5 series (C5x6.7 – C5x9)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C5x6.7 | 5 | 1.75 | 0.19 | 0.32 | 6.7 | 10 | 1.97 | 7.48 | 2.99 | 0.47 |
| C5x9 | 5 | 1.89 | 0.33 | 0.32 | 9 | 13.4 | 2.64 | 8.89 | 3.56 | 0.62 |
C6 series (C6x8.2 – C6x13)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C6x8.2 | 6 | 1.92 | 0.2 | 0.34 | 8.2 | 12.2 | 2.39 | 13.1 | 4.35 | 0.69 |
| C6x10.5 | 6 | 2.03 | 0.31 | 0.34 | 10.5 | 15.6 | 3.08 | 15.1 | 5.04 | 0.86 |
| C6x13 | 6 | 2.16 | 0.44 | 0.34 | 13 | 19.3 | 3.81 | 17.3 | 5.78 | 1.05 |
C7 series (C7x9.8 – C7x14.75)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C7x9.8 | 7 | 2.09 | 0.21 | 0.37 | 9.8 | 14.6 | 2.87 | 21.2 | 6.07 | 0.96 |
| C7x12.25 | 7 | 2.19 | 0.31 | 0.37 | 12.25 | 18.2 | 3.6 | 24.2 | 6.92 | 1.16 |
| C7x14.75 | 7 | 2.3 | 0.42 | 0.37 | 14.75 | 22 | 4.33 | 27.2 | 7.78 | 1.37 |
C8 series (C8x11.5 – C8x18.75)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C8x11.5 | 8 | 2.26 | 0.22 | 0.39 | 11.5 | 17.1 | 3.37 | 32.5 | 8.14 | 1.31 |
| C8x13.75 | 8 | 2.34 | 0.3 | 0.39 | 13.75 | 20.5 | 4.03 | 36.1 | 9.02 | 1.52 |
| C8x18.75 | 8 | 2.53 | 0.49 | 0.39 | 18.75 | 27.9 | 5.51 | 43.9 | 11 | 1.97 |
C9 series (C9x13.4 – C9x20)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C9x13.4 | 9 | 2.43 | 0.23 | 0.41 | 13.4 | 19.9 | 3.94 | 47.8 | 10.6 | 1.75 |
| C9x15 | 9 | 2.49 | 0.29 | 0.41 | 15 | 22.3 | 4.41 | 51 | 11.3 | 1.91 |
| C9x20 | 9 | 2.65 | 0.45 | 0.41 | 20 | 29.8 | 5.87 | 60.9 | 13.5 | 2.41 |
C10 series (C10x15.3 – C10x30)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C10x15.3 | 10 | 2.6 | 0.24 | 0.44 | 15.3 | 22.8 | 4.48 | 67.3 | 13.5 | 2.27 |
| C10x20 | 10 | 2.74 | 0.38 | 0.44 | 20 | 29.8 | 5.87 | 78.9 | 15.8 | 2.8 |
| C10x25 | 10 | 2.89 | 0.53 | 0.44 | 25 | 37.2 | 7.34 | 91.1 | 18.2 | 3.34 |
| C10x30 | 10 | 3.03 | 0.67 | 0.44 | 30 | 44.6 | 8.81 | 103 | 20.7 | 3.93 |
C12 series (C12x20.7 – C12x30)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C12x20.7 | 12 | 2.94 | 0.28 | 0.5 | 20.7 | 30.8 | 6.08 | 129 | 21.5 | 3.86 |
| C12x25 | 12 | 3.05 | 0.39 | 0.5 | 25 | 37.2 | 7.34 | 144 | 24 | 4.45 |
| C12x30 | 12 | 3.17 | 0.51 | 0.5 | 30 | 44.6 | 8.81 | 162 | 27 | 5.12 |
C15 series (C15x33.9 – C15x50)
| Shape | d (in) | bf (in) | tw (in) | tf (in) | lb/ft | kg/m | A (in²) | Ix (in⁴) | Sx (in³) | Iy (in⁴) |
|---|
| C15x33.9 | 15 | 3.4 | 0.4 | 0.65 | 33.9 | 50.4 | 9.95 | 315 | 42 | 8.07 |
| C15x40 | 15 | 3.52 | 0.52 | 0.65 | 40 | 59.5 | 11.8 | 348 | 46.5 | 9.17 |
| C15x50 | 15 | 3.72 | 0.72 | 0.65 | 50 | 74.4 | 14.7 | 404 | 53.8 | 11 |
Frequently asked questions
What do C-channel designations like C10x15.3 mean?
The first number is the exact depth in inches, the second is the weight in pounds per foot: a C10x15.3 is 10.00 in deep and weighs 15.3 lb/ft. Unlike W-shapes, channel depths within a family are all identical — heavier sizes grow in flange width and web thickness, never in depth.
What is the difference between C and MC channels?
C-channels (American Standard) follow the classic dimension series listed here. MC (miscellaneous) channels are everything else — typically deeper webs, wider flanges, or heavier weights for the same depth. C-channels are the stock item at every service center; MC sizes are less commonly held in inventory.
How do American C-channels compare to European UPN profiles?
They serve the same role and look nearly identical — both have tapered flanges. Dimensions differ: UPN is a metric series (UPN 100 = 100 mm deep), C is imperial (C4 ≈ 102 mm). The sections are not interchangeable in a design, but our UPN table lets you find the closest metric equivalent quickly.
Why is the flange thickness an average value?
C-channel flanges taper at a slope of about 1:6 — thick at the web, thinner at the tip. The AISC tables (and this chart) list the average thickness, which is what the section properties are computed with. Parallel-flange channels (like European UPE) do not have this quirk.
Values are entered from the governing standard’s published tables and cross-checked programmatically against its mass and section formulas before publication. Spotted an error? Write to advertising@metalabout.net — verified corrections ship within days. About