W40x215 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W40x215 is an American wide-flange beam 39 inches (990.6 mm) deep with a 15.8 in (401.3 mm) flange, weighing 215 pounds per foot (320 kg/m) — that is what the "215" 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 | 15.8 in (401.3 mm) |
| Web thickness tw | 0.65 in (16.5 mm) |
| Flange thickness tf | 1.22 in (31 mm) |
Weight & Cross-Section
| Weight per foot | 215 lb/ft (320 kg/m) |
| 20 ft bar | 4,300 lb |
| 40 ft bar | 8,600 lb |
| Area A | 63.5 in² (409.7 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 16,700 in⁴ (695,104 cm⁴) |
| Section modulus Sx | 859 in³ (14,076 cm³) |
| Radius of gyration rx | 16.2 in |
| Moment of inertia Iy | 803 in⁴ (33,423 cm⁴) |
| Section modulus Sy | 101 in³ (1,655 cm³) |
| Radius of gyration ry | 3.54 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W40x199 | 38.7 × 15.8 | 199 | 14,900 | 770 | −7 % | −11 % |
| W40x215 (this page) | 39 × 15.8 | 215 | 16,700 | 859 | — | — |
Deflection example
A simply supported W40x215 spanning 62 ft with a 10 kip point load at midspan deflects 0.18 in (E = 29,000 ksi, Ix = 16,700 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 W40x215 beam weigh?
W40x215 weighs 215 pounds per foot (320 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 4,300 lb and a 40 ft bar 8,600 lb.
What are the dimensions of a W40x215?
W40x215 is 39 in (990.6 mm) deep with a 15.8 in (401.3 mm) wide flange. The web is 0.65 in thick and the flanges are 1.22 in thick. Note the actual depth differs from the nominal W40 label — always design with the actual value.
What are the dimensions of a W40x215 in mm?
W40x215 is 990.6 mm deep with a 401.3 mm wide flange; the web is 16.5 mm and the flange 31 mm thick. In metric section properties: Ix = 695,104 cm⁴, Sx = 14,076 cm³.
How much does a W40x215 weigh in kg?
320 kg per meter. A 6 m bar weighs 1,920 kg and a 12 m bar 3,840 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W40x215?
About the strong axis, Ix = 16,700 in⁴ (695,104 cm⁴) with section modulus Sx = 859 in³. About the weak axis, Iy = 803 in⁴ and Sy = 101 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W40x215 or W40x199 — what does one size down change?
W40x199 is about 7% lighter (199 vs 215 lb/ft) but about 11% less stiff (Ix 14,900 vs 16,700 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