W8x58 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W8x58 is an American wide-flange beam 8.75 inches (222.3 mm) deep with a 8.22 in (208.8 mm) flange, weighing 58 pounds per foot (86.3 kg/m) — that is what the "58" 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 | 8.75 in (222.3 mm) |
| Flange width bf | 8.22 in (208.8 mm) |
| Web thickness tw | 0.51 in (13 mm) |
| Flange thickness tf | 0.81 in (20.6 mm) |
Weight & Cross-Section
| Weight per foot | 58 lb/ft (86.3 kg/m) |
| 20 ft bar | 1,160 lb |
| 40 ft bar | 2,320 lb |
| Area A | 17.1 in² (110.3 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 228 in⁴ (9,490 cm⁴) |
| Section modulus Sx | 52 in³ (852 cm³) |
| Radius of gyration rx | 3.65 in |
| Moment of inertia Iy | 75.1 in⁴ (3,126 cm⁴) |
| Section modulus Sy | 18.3 in³ (300 cm³) |
| Radius of gyration ry | 2.1 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W8x48 | 8.5 × 8.11 | 48 | 184 | 43.2 | −17 % | −19 % |
| W8x58 (this page) | 8.75 × 8.22 | 58 | 228 | 52 | — | — |
| W8x67 | 9 × 8.28 | 67 | 272 | 60.4 | +16 % | +19 % |
Deflection example
A simply supported W8x58 spanning 14 ft with a 10 kip point load at midspan deflects 0.15 in (E = 29,000 ksi, Ix = 228 in⁴). The L/360 serviceability limit for this span is 0.47 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W8x58 beam weigh?
W8x58 weighs 58 pounds per foot (86.3 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 1,160 lb and a 40 ft bar 2,320 lb.
What are the dimensions of a W8x58?
W8x58 is 8.75 in (222.3 mm) deep with a 8.22 in (208.8 mm) wide flange. The web is 0.51 in thick and the flanges are 0.81 in thick. Note the actual depth differs from the nominal W8 label — always design with the actual value.
What are the dimensions of a W8x58 in mm?
W8x58 is 222.3 mm deep with a 208.8 mm wide flange; the web is 13 mm and the flange 20.6 mm thick. In metric section properties: Ix = 9,490 cm⁴, Sx = 852 cm³.
How much does a W8x58 weigh in kg?
86.3 kg per meter. A 6 m bar weighs 518 kg and a 12 m bar 1,036 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W8x58?
About the strong axis, Ix = 228 in⁴ (9,490 cm⁴) with section modulus Sx = 52 in³. About the weak axis, Iy = 75.1 in⁴ and Sy = 18.3 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W8x58 or W8x67 — what does one size up change?
W8x67 is about 16% heavier (67 vs 58 lb/ft) but about 19% stiffer (Ix 272 vs 228 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