W6x25 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W6x25 is an American wide-flange beam 6.38 inches (162.1 mm) deep with a 6.08 in (154.4 mm) flange, weighing 25 pounds per foot (37.2 kg/m) — that is what the "25" 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 | 6.38 in (162.1 mm) |
| Flange width bf | 6.08 in (154.4 mm) |
| Web thickness tw | 0.32 in (8.1 mm) |
| Flange thickness tf | 0.455 in (11.6 mm) |
Weight & Cross-Section
| Weight per foot | 25 lb/ft (37.2 kg/m) |
| 20 ft bar | 500 lb |
| 40 ft bar | 1,000 lb |
| Area A | 7.34 in² (47.4 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 53.4 in⁴ (2,223 cm⁴) |
| Section modulus Sx | 16.7 in³ (274 cm³) |
| Radius of gyration rx | 2.7 in |
| Moment of inertia Iy | 17.1 in⁴ (712 cm⁴) |
| Section modulus Sy | 5.61 in³ (92 cm³) |
| Radius of gyration ry | 1.52 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W6x20 | 6.2 × 6.02 | 20 | 41.4 | 13.4 | −20 % | −22 % |
| W6x25 (this page) | 6.38 × 6.08 | 25 | 53.4 | 16.7 | — | — |
Deflection example
A simply supported W6x25 spanning 10 ft with a 10 kip point load at midspan deflects 0.23 in (E = 29,000 ksi, Ix = 53.4 in⁴). The L/360 serviceability limit for this span is 0.33 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W6x25 beam weigh?
W6x25 weighs 25 pounds per foot (37.2 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 500 lb and a 40 ft bar 1,000 lb.
What are the dimensions of a W6x25?
W6x25 is 6.38 in (162.1 mm) deep with a 6.08 in (154.4 mm) wide flange. The web is 0.32 in thick and the flanges are 0.46 in thick. Note the actual depth differs from the nominal W6 label — always design with the actual value.
What are the dimensions of a W6x25 in mm?
W6x25 is 162.1 mm deep with a 154.4 mm wide flange; the web is 8.1 mm and the flange 11.6 mm thick. In metric section properties: Ix = 2,223 cm⁴, Sx = 274 cm³.
How much does a W6x25 weigh in kg?
37.2 kg per meter. A 6 m bar weighs 223 kg and a 12 m bar 446 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W6x25?
About the strong axis, Ix = 53.4 in⁴ (2,223 cm⁴) with section modulus Sx = 16.7 in³. About the weak axis, Iy = 17.1 in⁴ and Sy = 5.61 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W6x25 or W6x20 — what does one size down change?
W6x20 is about 20% lighter (20 vs 25 lb/ft) but about 22% less stiff (Ix 41.4 vs 53.4 in⁴). Check deflection before downsizing — stiffness falls much faster than weight.
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