W10x39 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W10x39 is an American wide-flange beam 9.92 inches (252 mm) deep with a 7.99 in (202.9 mm) flange, weighing 39 pounds per foot (58 kg/m) — that is what the "39" in the designation means. All values below are the standard AISC published section properties used in US structural design, with metric equivalents alongside.
Typical uses: floor and roof framing, columns, headers, and general steel construction. For a quick stiffness check, see the deflection example below or open the beam calculator with your own span and load.
Dimensions
| Depth d | 9.92 in (252 mm) |
| Flange width bf | 7.99 in (202.9 mm) |
| Web thickness tw | 0.315 in (8 mm) |
| Flange thickness tf | 0.53 in (13.5 mm) |
Weight & Cross-Section
| Weight per foot | 39 lb/ft (58 kg/m) |
| 20 ft bar | 780 lb |
| 40 ft bar | 1,560 lb |
| Area A | 11.5 in² (74.2 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 209 in⁴ (8,699 cm⁴) |
| Section modulus Sx | 42.1 in³ (690 cm³) |
| Radius of gyration rx | 4.27 in |
| Moment of inertia Iy | 45 in⁴ (1,873 cm⁴) |
| Section modulus Sy | 11.3 in³ (185 cm³) |
| Radius of gyration ry | 1.98 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W10x33 | 9.73 × 7.96 | 33 | 171 | 35 | −15 % | −18 % |
| W10x39 (this page) | 9.92 × 7.99 | 39 | 209 | 42.1 | — | — |
| W10x45 | 10.1 × 8.02 | 45 | 248 | 49.1 | +15 % | +19 % |
Deflection example
A simply supported W10x39 spanning 16 ft with a 10 kip point load at midspan deflects 0.24 in (E = 29,000 ksi, Ix = 209 in⁴). The L/360 serviceability limit for this span is 0.53 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W10x39 beam weigh?
W10x39 weighs 39 pounds per foot (58 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 780 lb and a 40 ft bar 1,560 lb.
What are the dimensions of a W10x39?
W10x39 is 9.92 in (252 mm) deep with a 7.99 in (202.9 mm) wide flange. The web is 0.32 in thick and the flanges are 0.53 in thick. Note the actual depth differs from the nominal W10 label — always design with the actual value.
What are the dimensions of a W10x39 in mm?
W10x39 is 252 mm deep with a 202.9 mm wide flange; the web is 8 mm and the flange 13.5 mm thick. In metric section properties: Ix = 8,699 cm⁴, Sx = 690 cm³.
How much does a W10x39 weigh in kg?
58 kg per meter. A 6 m bar weighs 348 kg and a 12 m bar 696 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W10x39?
About the strong axis, Ix = 209 in⁴ (8,699 cm⁴) with section modulus Sx = 42.1 in³. About the weak axis, Iy = 45 in⁴ and Sy = 11.3 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W10x39 or W10x45 — what does one size up change?
W10x45 is about 15% heavier (45 vs 39 lb/ft) but about 19% stiffer (Ix 248 vs 209 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