W6x12 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W6x12 is an American wide-flange beam 6.03 inches (153.2 mm) deep with a 4 in (101.6 mm) flange, weighing 12 pounds per foot (17.9 kg/m) — that is what the "12" 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 | 6.03 in (153.2 mm) |
| Flange width bf | 4 in (101.6 mm) |
| Web thickness tw | 0.23 in (5.8 mm) |
| Flange thickness tf | 0.28 in (7.1 mm) |
Weight & Cross-Section
| Weight per foot | 12 lb/ft (17.9 kg/m) |
| 20 ft bar | 240 lb |
| 40 ft bar | 480 lb |
| Area A | 3.55 in² (22.9 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 22.1 in⁴ (920 cm⁴) |
| Section modulus Sx | 7.31 in³ (120 cm³) |
| Radius of gyration rx | 2.49 in |
| Moment of inertia Iy | 2.99 in⁴ (124 cm⁴) |
| Section modulus Sy | 1.5 in³ (25 cm³) |
| Radius of gyration ry | 0.92 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W6x9 | 5.9 × 3.94 | 9 | 16.4 | 5.56 | −25 % | −26 % |
| W6x12 (this page) | 6.03 × 4 | 12 | 22.1 | 7.31 | — | — |
| W6x15 | 5.99 × 5.99 | 15 | 29.1 | 9.72 | +25 % | +32 % |
Deflection example
A simply supported W6x12 spanning 10 ft with a 10 kip point load at midspan deflects 0.56 in (E = 29,000 ksi, Ix = 22.1 in⁴). The L/360 serviceability limit for this span is 0.33 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W6x12 beam weigh?
W6x12 weighs 12 pounds per foot (17.9 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 240 lb and a 40 ft bar 480 lb.
What are the dimensions of a W6x12?
W6x12 is 6.03 in (153.2 mm) deep with a 4 in (101.6 mm) wide flange. The web is 0.23 in thick and the flanges are 0.28 in thick. Note the actual depth differs from the nominal W6 label — always design with the actual value.
What are the dimensions of a W6x12 in mm?
W6x12 is 153.2 mm deep with a 101.6 mm wide flange; the web is 5.8 mm and the flange 7.1 mm thick. In metric section properties: Ix = 920 cm⁴, Sx = 120 cm³.
How much does a W6x12 weigh in kg?
17.9 kg per meter. A 6 m bar weighs 107 kg and a 12 m bar 214 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W6x12?
About the strong axis, Ix = 22.1 in⁴ (920 cm⁴) with section modulus Sx = 7.31 in³. About the weak axis, Iy = 2.99 in⁴ and Sy = 1.5 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W6x12 or W6x15 — what does one size up change?
W6x15 is about 25% heavier (15 vs 12 lb/ft) but about 32% stiffer (Ix 29.1 vs 22.1 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