W4x13 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W4x13 is an American wide-flange beam 4.16 inches (105.7 mm) deep with a 4.06 in (103.1 mm) flange, weighing 13 pounds per foot (19.3 kg/m) — that is what the "13" 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 | 4.16 in (105.7 mm) |
| Flange width bf | 4.06 in (103.1 mm) |
| Web thickness tw | 0.28 in (7.1 mm) |
| Flange thickness tf | 0.345 in (8.8 mm) |
Weight & Cross-Section
| Weight per foot | 13 lb/ft (19.3 kg/m) |
| 20 ft bar | 260 lb |
| 40 ft bar | 520 lb |
| Area A | 3.83 in² (24.7 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 11.3 in⁴ (470 cm⁴) |
| Section modulus Sx | 5.46 in³ (89 cm³) |
| Radius of gyration rx | 1.72 in |
| Moment of inertia Iy | 3.86 in⁴ (161 cm⁴) |
| Section modulus Sy | 1.9 in³ (31 cm³) |
| Radius of gyration ry | 1 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W4x13 (this page) | 4.16 × 4.06 | 13 | 11.3 | 5.46 | — | — |
Deflection example
A simply supported W4x13 spanning 7 ft with a 10 kip point load at midspan deflects 0.38 in (E = 29,000 ksi, Ix = 11.3 in⁴). The L/360 serviceability limit for this span is 0.23 in — the shape does NOT pass this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W4x13 beam weigh?
W4x13 weighs 13 pounds per foot (19.3 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 260 lb and a 40 ft bar 520 lb.
What are the dimensions of a W4x13?
W4x13 is 4.16 in (105.7 mm) deep with a 4.06 in (103.1 mm) wide flange. The web is 0.28 in thick and the flanges are 0.35 in thick. Note the actual depth differs from the nominal W4 label — always design with the actual value.
What are the dimensions of a W4x13 in mm?
W4x13 is 105.7 mm deep with a 103.1 mm wide flange; the web is 7.1 mm and the flange 8.8 mm thick. In metric section properties: Ix = 470 cm⁴, Sx = 89 cm³.
How much does a W4x13 weigh in kg?
19.3 kg per meter. A 6 m bar weighs 116 kg and a 12 m bar 232 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W4x13?
About the strong axis, Ix = 11.3 in⁴ (470 cm⁴) with section modulus Sx = 5.46 in³. About the weak axis, Iy = 3.86 in⁴ and Sy = 1.9 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
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