W40x199 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W40x199 is an American wide-flange beam 38.7 inches (983 mm) deep with a 15.8 in (401.3 mm) flange, weighing 199 pounds per foot (296.2 kg/m) — that is what the "199" 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.
W40x199: cross-section drawn to scale from the AISC dimensions (d 38.7, bf 15.8, tw 0.65, tf 1.07 in)Dimensions
| Depth d | 38.7 in (983 mm) |
| Flange width bf | 15.8 in (401.3 mm) |
| Web thickness tw | 0.65 in (16.5 mm) |
| Flange thickness tf | 1.07 in (27.2 mm) |
Weight & Cross-Section
| Weight per foot | 199 lb/ft (296.2 kg/m) |
| 20 ft bar | 3,980 lb |
| 40 ft bar | 7,960 lb |
| Area A | 58.8 in² (379.4 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 14,900 in⁴ (620,183 cm⁴) |
| Section modulus Sx | 770 in³ (12,618 cm³) |
| Radius of gyration rx | 16 in |
| Moment of inertia Iy | 695 in⁴ (28,928 cm⁴) |
| Section modulus Sy | 88.2 in³ (1,445 cm³) |
| Radius of gyration ry | 3.45 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|
| W40x183 | 39 × 11.8 | 183 | 13,200 | 675 | −8 % | −11 % |
| W40x199 (this page) | 38.7 × 15.8 | 199 | 14,900 | 770 | — | — |
| W40x215 | 39 × 15.8 | 215 | 16,700 | 859 | +8 % | +12 % |
Deflection example
A simply supported W40x199 spanning 62 ft with a 10 kip point load at midspan deflects 0.2 in (E = 29,000 ksi, Ix = 14,900 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 W40x199 beam weigh?
W40x199 weighs 199 pounds per foot (296.2 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 3,980 lb and a 40 ft bar 7,960 lb.
What are the dimensions of a W40x199?
W40x199 is 38.7 in (983 mm) deep with a 15.8 in (401.3 mm) wide flange. The web is 0.65 in thick and the flanges are 1.07 in thick. Note the actual depth differs from the nominal W40 label — always design with the actual value.
What are the dimensions of a W40x199 in mm?
W40x199 is 983 mm deep with a 401.3 mm wide flange; the web is 16.5 mm and the flange 27.2 mm thick. In metric section properties: Ix = 620,183 cm⁴, Sx = 12,618 cm³.
How much does a W40x199 weigh in kg?
296.2 kg per meter. A 6 m bar weighs 1,777 kg and a 12 m bar 3,554 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W40x199?
About the strong axis, Ix = 14,900 in⁴ (620,183 cm⁴) with section modulus Sx = 770 in³. About the weak axis, Iy = 695 in⁴ and Sy = 88.2 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W40x199 or W40x215 — what does one size up change?
W40x215 is about 8% heavier (215 vs 199 lb/ft) but about 12% stiffer (Ix 16,700 vs 14,900 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