W10x77 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W10x77 is an American wide-flange beam 10.6 inches (269.2 mm) deep with a 10.2 in (259.1 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 | 10.6 in (269.2 mm) |
| Flange width bf | 10.2 in (259.1 mm) |
| Web thickness tw | 0.53 in (13.5 mm) |
| Flange thickness tf | 0.87 in (22.1 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 | 455 in⁴ (18,938 cm⁴) |
| Section modulus Sx | 85.9 in³ (1,408 cm³) |
| Radius of gyration rx | 4.49 in |
| Moment of inertia Iy | 154 in⁴ (6,410 cm⁴) |
| Section modulus Sy | 30.1 in³ (493 cm³) |
| Radius of gyration ry | 2.6 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W10x68 | 10.4 × 10.1 | 68 | 394 | 75.7 | −12 % | −13 % |
| W10x77 (this page) | 10.6 × 10.2 | 77 | 455 | 85.9 | — | — |
| W10x88 | 10.8 × 10.3 | 88 | 534 | 98.5 | +14 % | +17 % |
Deflection example
A simply supported W10x77 spanning 17 ft with a 10 kip point load at midspan deflects 0.13 in (E = 29,000 ksi, Ix = 455 in⁴). The L/360 serviceability limit for this span is 0.57 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W10x77 beam weigh?
W10x77 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 W10x77?
W10x77 is 10.6 in (269.2 mm) deep with a 10.2 in (259.1 mm) wide flange. The web is 0.53 in thick and the flanges are 0.87 in thick. Note the actual depth differs from the nominal W10 label — always design with the actual value.
What are the dimensions of a W10x77 in mm?
W10x77 is 269.2 mm deep with a 259.1 mm wide flange; the web is 13.5 mm and the flange 22.1 mm thick. In metric section properties: Ix = 18,938 cm⁴, Sx = 1,408 cm³.
How much does a W10x77 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 W10x77?
About the strong axis, Ix = 455 in⁴ (18,938 cm⁴) with section modulus Sx = 85.9 in³. About the weak axis, Iy = 154 in⁴ and Sy = 30.1 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W10x77 or W10x88 — what does one size up change?
W10x88 is about 14% heavier (88 vs 77 lb/ft) but about 17% stiffer (Ix 534 vs 455 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