C10x20 — Dimensions, Weight & Section Properties
American Standard (C) channel per ASTM A6 / AISC Steel Construction Manual
C10x20 is an American Standard steel channel 10 inches (254 mm) deep with a 2.74 in (69.6 mm) flange, weighing 20 pounds per foot (29.8 kg/m) — that is what the "20" in the designation means. All values below are the standard AISC published section properties used in US structural design, with metric equivalents alongside. Channel flanges are tapered, so the flange thickness listed is the AISC average value.
Typical uses: stair stringers, trailer and equipment frames, rails, lintels, and bracing — anywhere a flat back against a wall or web is handy. For a quick stiffness check, see the deflection example below or open the beam calculator with your own span and load.
C10x20: cross-section drawn to scale from the AISC dimensions (d 10, bf 2.74, tw 0.379, tf 0.436 in)Dimensions
| Depth d | 10 in (254 mm) |
| Flange width bf | 2.74 in (69.6 mm) |
| Web thickness tw | 0.379 in (9.6 mm) |
| Avg. flange thickness tf | 0.436 in (11.1 mm) |
Weight & Cross-Section
| Weight per foot | 20 lb/ft (29.8 kg/m) |
| 20 ft bar | 400 lb |
| 40 ft bar | 800 lb |
| Area A | 5.87 in² (37.9 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 78.9 in⁴ (3,284 cm⁴) |
| Section modulus Sx | 15.8 in³ (259 cm³) |
| Radius of gyration rx | 3.66 in |
| Moment of inertia Iy | 2.8 in⁴ (117 cm⁴) |
| Section modulus Sy | 1.31 in³ (21 cm³) |
| Radius of gyration ry | 0.69 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|
| C10x15.3 | 10 × 2.6 | 15.3 | 67.3 | 13.5 | −23 % | −15 % |
| C10x20 (this page) | 10 × 2.74 | 20 | 78.9 | 15.8 | — | — |
| C10x25 | 10 × 2.89 | 25 | 91.1 | 18.2 | +25 % | +15 % |
Deflection example
A simply supported C10x20 spanning 16 ft with a 10 kip point load at midspan deflects 0.64 in (E = 29,000 ksi, Ix = 78.9 in⁴). The L/360 serviceability limit for this span is 0.53 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a C10x20 channel weigh?
C10x20 weighs 20 pounds per foot (29.8 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 400 lb and a 40 ft bar 800 lb.
What are the dimensions of a C10x20?
C10x20 is exactly 10 in (254 mm) deep with a 2.74 in (69.6 mm) wide flange. The web is 0.38 in thick; the tapered flanges average 0.44 in. Unlike W-shapes, C-channel depths are exact — a C10 is always 10.00 in deep.
What are the dimensions of a C10x20 in mm?
C10x20 is 254 mm deep with a 69.6 mm wide flange; the web is 9.6 mm and the flange 11.1 mm thick. In metric section properties: Ix = 3,284 cm⁴, Sx = 259 cm³.
How much does a C10x20 weigh in kg?
29.8 kg per meter. A 6 m bar weighs 179 kg and a 12 m bar 357 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a C10x20?
About the strong axis, Ix = 78.9 in⁴ (3,284 cm⁴) with section modulus Sx = 15.8 in³. About the weak axis, Iy = 2.8 in⁴ and Sy = 1.31 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
C10x20 or C10x25 — what does one size up change?
C10x25 is about 25% heavier (25 vs 20 lb/ft) but about 15% stiffer (Ix 91.1 vs 78.9 in⁴). Going one step up within the same depth group is usually the cheapest way to cut deflection.
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