W24x55 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W24x55 is an American wide-flange beam 23.6 inches (599.4 mm) deep with a 7.01 in (178.1 mm) flange, weighing 55 pounds per foot (81.9 kg/m) — that is what the "55" 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 | 23.6 in (599.4 mm) |
| Flange width bf | 7.01 in (178.1 mm) |
| Web thickness tw | 0.395 in (10 mm) |
| Flange thickness tf | 0.505 in (12.8 mm) |
Weight & Cross-Section
| Weight per foot | 55 lb/ft (81.9 kg/m) |
| 20 ft bar | 1,100 lb |
| 40 ft bar | 2,200 lb |
| Area A | 16.2 in² (104.5 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 1,350 in⁴ (56,191 cm⁴) |
| Section modulus Sx | 114 in³ (1,868 cm³) |
| Radius of gyration rx | 9.11 in |
| Moment of inertia Iy | 29.1 in⁴ (1,211 cm⁴) |
| Section modulus Sy | 8.3 in³ (136 cm³) |
| Radius of gyration ry | 1.34 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W24x55 (this page) | 23.6 × 7.01 | 55 | 1,350 | 114 | — | — |
| W24x62 | 23.7 × 7.04 | 62 | 1,550 | 131 | +13 % | +15 % |
Deflection example
A simply supported W24x55 spanning 38 ft with a 10 kip point load at midspan deflects 0.51 in (E = 29,000 ksi, Ix = 1,350 in⁴). The L/360 serviceability limit for this span is 1.27 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W24x55 beam weigh?
W24x55 weighs 55 pounds per foot (81.9 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 1,100 lb and a 40 ft bar 2,200 lb.
What are the dimensions of a W24x55?
W24x55 is 23.6 in (599.4 mm) deep with a 7.01 in (178.1 mm) wide flange. The web is 0.4 in thick and the flanges are 0.51 in thick. Note the actual depth differs from the nominal W24 label — always design with the actual value.
What are the dimensions of a W24x55 in mm?
W24x55 is 599.4 mm deep with a 178.1 mm wide flange; the web is 10 mm and the flange 12.8 mm thick. In metric section properties: Ix = 56,191 cm⁴, Sx = 1,868 cm³.
How much does a W24x55 weigh in kg?
81.9 kg per meter. A 6 m bar weighs 491 kg and a 12 m bar 982 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W24x55?
About the strong axis, Ix = 1,350 in⁴ (56,191 cm⁴) with section modulus Sx = 114 in³. About the weak axis, Iy = 29.1 in⁴ and Sy = 8.3 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W24x55 or W24x62 — what does one size up change?
W24x62 is about 13% heavier (62 vs 55 lb/ft) but about 15% stiffer (Ix 1,550 vs 1,350 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