W16x45 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W16x45 is an American wide-flange beam 16.1 inches (408.9 mm) deep with a 7.04 in (178.8 mm) flange, weighing 45 pounds per foot (67 kg/m) — that is what the "45" 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 | 16.1 in (408.9 mm) |
| Flange width bf | 7.04 in (178.8 mm) |
| Web thickness tw | 0.345 in (8.8 mm) |
| Flange thickness tf | 0.565 in (14.4 mm) |
Weight & Cross-Section
| Weight per foot | 45 lb/ft (67 kg/m) |
| 20 ft bar | 900 lb |
| 40 ft bar | 1,800 lb |
| Area A | 13.3 in² (85.8 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 586 in⁴ (24,391 cm⁴) |
| Section modulus Sx | 72.7 in³ (1,191 cm³) |
| Radius of gyration rx | 6.65 in |
| Moment of inertia Iy | 32.8 in⁴ (1,365 cm⁴) |
| Section modulus Sy | 9.34 in³ (153 cm³) |
| Radius of gyration ry | 1.57 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W16x40 | 16 × 7 | 40 | 518 | 64.7 | −11 % | −12 % |
| W16x45 (this page) | 16.1 × 7.04 | 45 | 586 | 72.7 | — | — |
| W16x50 | 16.3 × 7.07 | 50 | 659 | 81 | +11 % | +12 % |
Deflection example
A simply supported W16x45 spanning 26 ft with a 10 kip point load at midspan deflects 0.37 in (E = 29,000 ksi, Ix = 586 in⁴). The L/360 serviceability limit for this span is 0.87 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W16x45 beam weigh?
W16x45 weighs 45 pounds per foot (67 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 900 lb and a 40 ft bar 1,800 lb.
What are the dimensions of a W16x45?
W16x45 is 16.1 in (408.9 mm) deep with a 7.04 in (178.8 mm) wide flange. The web is 0.35 in thick and the flanges are 0.57 in thick. Note the actual depth differs from the nominal W16 label — always design with the actual value.
What are the dimensions of a W16x45 in mm?
W16x45 is 408.9 mm deep with a 178.8 mm wide flange; the web is 8.8 mm and the flange 14.4 mm thick. In metric section properties: Ix = 24,391 cm⁴, Sx = 1,191 cm³.
How much does a W16x45 weigh in kg?
67 kg per meter. A 6 m bar weighs 402 kg and a 12 m bar 804 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W16x45?
About the strong axis, Ix = 586 in⁴ (24,391 cm⁴) with section modulus Sx = 72.7 in³. About the weak axis, Iy = 32.8 in⁴ and Sy = 9.34 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W16x45 or W16x50 — what does one size up change?
W16x50 is about 11% heavier (50 vs 45 lb/ft) but about 12% stiffer (Ix 659 vs 586 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