W16x77 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W16x77 is an American wide-flange beam 16.5 inches (419.1 mm) deep with a 10.3 in (261.6 mm) flange, weighing 77 pounds per foot (114.6 kg/m) — that is what the "77" 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 | 16.5 in (419.1 mm) |
| Flange width bf | 10.3 in (261.6 mm) |
| Web thickness tw | 0.455 in (11.6 mm) |
| Flange thickness tf | 0.76 in (19.3 mm) |
Weight & Cross-Section
| Weight per foot | 77 lb/ft (114.6 kg/m) |
| 20 ft bar | 1,540 lb |
| 40 ft bar | 3,080 lb |
| Area A | 22.6 in² (145.8 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 1,110 in⁴ (46,202 cm⁴) |
| Section modulus Sx | 134 in³ (2,196 cm³) |
| Radius of gyration rx | 7 in |
| Moment of inertia Iy | 138 in⁴ (5,744 cm⁴) |
| Section modulus Sy | 26.9 in³ (441 cm³) |
| Radius of gyration ry | 2.47 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W16x67 | 16.3 × 10.2 | 67 | 954 | 117 | −13 % | −14 % |
| W16x77 (this page) | 16.5 × 10.3 | 77 | 1,110 | 134 | — | — |
| W16x89 | 16.8 × 10.4 | 89 | 1,300 | 155 | +16 % | +17 % |
Deflection example
A simply supported W16x77 spanning 26 ft with a 10 kip point load at midspan deflects 0.2 in (E = 29,000 ksi, Ix = 1,110 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 W16x77 beam weigh?
W16x77 weighs 77 pounds per foot (114.6 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 1,540 lb and a 40 ft bar 3,080 lb.
What are the dimensions of a W16x77?
W16x77 is 16.5 in (419.1 mm) deep with a 10.3 in (261.6 mm) wide flange. The web is 0.46 in thick and the flanges are 0.76 in thick. Note the actual depth differs from the nominal W16 label — always design with the actual value.
What are the dimensions of a W16x77 in mm?
W16x77 is 419.1 mm deep with a 261.6 mm wide flange; the web is 11.6 mm and the flange 19.3 mm thick. In metric section properties: Ix = 46,202 cm⁴, Sx = 2,196 cm³.
How much does a W16x77 weigh in kg?
114.6 kg per meter. A 6 m bar weighs 688 kg and a 12 m bar 1,375 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W16x77?
About the strong axis, Ix = 1,110 in⁴ (46,202 cm⁴) with section modulus Sx = 134 in³. About the weak axis, Iy = 138 in⁴ and Sy = 26.9 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W16x77 or W16x89 — what does one size up change?
W16x89 is about 16% heavier (89 vs 77 lb/ft) but about 17% stiffer (Ix 1,300 vs 1,110 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