W40x183 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W40x183 is an American wide-flange beam 39 inches (990.6 mm) deep with a 11.8 in (299.7 mm) flange, weighing 183 pounds per foot (272.3 kg/m) — that is what the "183" 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 | 39 in (990.6 mm) |
| Flange width bf | 11.8 in (299.7 mm) |
| Web thickness tw | 0.65 in (16.5 mm) |
| Flange thickness tf | 1.2 in (30.5 mm) |
Weight & Cross-Section
| Weight per foot | 183 lb/ft (272.3 kg/m) |
| 20 ft bar | 3,660 lb |
| 40 ft bar | 7,320 lb |
| Area A | 53.3 in² (343.9 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 13,200 in⁴ (549,424 cm⁴) |
| Section modulus Sx | 675 in³ (11,061 cm³) |
| Radius of gyration rx | 15.7 in |
| Moment of inertia Iy | 331 in⁴ (13,777 cm⁴) |
| Section modulus Sy | 56 in³ (918 cm³) |
| Radius of gyration ry | 2.49 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W40x167 | 38.6 × 11.8 | 167 | 11,600 | 600 | −9 % | −12 % |
| W40x183 (this page) | 39 × 11.8 | 183 | 13,200 | 675 | — | — |
| W40x199 | 38.7 × 15.8 | 199 | 14,900 | 770 | +9 % | +13 % |
Deflection example
A simply supported W40x183 spanning 62 ft with a 10 kip point load at midspan deflects 0.22 in (E = 29,000 ksi, Ix = 13,200 in⁴). The L/360 serviceability limit for this span is 2.07 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W40x183 beam weigh?
W40x183 weighs 183 pounds per foot (272.3 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 3,660 lb and a 40 ft bar 7,320 lb.
What are the dimensions of a W40x183?
W40x183 is 39 in (990.6 mm) deep with a 11.8 in (299.7 mm) wide flange. The web is 0.65 in thick and the flanges are 1.2 in thick. Note the actual depth differs from the nominal W40 label — always design with the actual value.
What are the dimensions of a W40x183 in mm?
W40x183 is 990.6 mm deep with a 299.7 mm wide flange; the web is 16.5 mm and the flange 30.5 mm thick. In metric section properties: Ix = 549,424 cm⁴, Sx = 11,061 cm³.
How much does a W40x183 weigh in kg?
272.3 kg per meter. A 6 m bar weighs 1,634 kg and a 12 m bar 3,268 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W40x183?
About the strong axis, Ix = 13,200 in⁴ (549,424 cm⁴) with section modulus Sx = 675 in³. About the weak axis, Iy = 331 in⁴ and Sy = 56 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W40x183 or W40x199 — what does one size up change?
W40x199 is about 9% heavier (199 vs 183 lb/ft) but about 13% stiffer (Ix 14,900 vs 13,200 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