W12x336 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W12x336 is an American wide-flange beam 16.8 inches (426.7 mm) deep with a 13.4 in (340.4 mm) flange, weighing 336 pounds per foot (500 kg/m) — that is what the "336" 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 | 16.8 in (426.7 mm) |
| Flange width bf | 13.4 in (340.4 mm) |
| Web thickness tw | 1.78 in (45.2 mm) |
| Flange thickness tf | 2.96 in (75.2 mm) |
Weight & Cross-Section
| Weight per foot | 336 lb/ft (500 kg/m) |
| 20 ft bar | 6,720 lb |
| 40 ft bar | 13,440 lb |
| Area A | 98.9 in² (638.1 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 4,060 in⁴ (168,989 cm⁴) |
| Section modulus Sx | 483 in³ (7,915 cm³) |
| Radius of gyration rx | 6.41 in |
| Moment of inertia Iy | 1,190 in⁴ (49,531 cm⁴) |
| Section modulus Sy | 177 in³ (2,900 cm³) |
| Radius of gyration ry | 3.47 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W12x305 | 16.3 × 13.2 | 305 | 3,550 | 435 | −9 % | −13 % |
| W12x336 (this page) | 16.8 × 13.4 | 336 | 4,060 | 483 | — | — |
Deflection example
A simply supported W12x336 spanning 27 ft with a 10 kip point load at midspan deflects 0.06 in (E = 29,000 ksi, Ix = 4,060 in⁴). The L/360 serviceability limit for this span is 0.9 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W12x336 beam weigh?
W12x336 weighs 336 pounds per foot (500 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 6,720 lb and a 40 ft bar 13,440 lb.
What are the dimensions of a W12x336?
W12x336 is 16.8 in (426.7 mm) deep with a 13.4 in (340.4 mm) wide flange. The web is 1.78 in thick and the flanges are 2.96 in thick. Note the actual depth differs from the nominal W12 label — always design with the actual value.
What are the dimensions of a W12x336 in mm?
W12x336 is 426.7 mm deep with a 340.4 mm wide flange; the web is 45.2 mm and the flange 75.2 mm thick. In metric section properties: Ix = 168,989 cm⁴, Sx = 7,915 cm³.
How much does a W12x336 weigh in kg?
500 kg per meter. A 6 m bar weighs 3,000 kg and a 12 m bar 6,000 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W12x336?
About the strong axis, Ix = 4,060 in⁴ (168,989 cm⁴) with section modulus Sx = 483 in³. About the weak axis, Iy = 1,190 in⁴ and Sy = 177 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W12x336 or W12x305 — what does one size down change?
W12x305 is about 9% lighter (305 vs 336 lb/ft) but about 13% less stiff (Ix 3,550 vs 4,060 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