W27x129 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W27x129 is an American wide-flange beam 27.6 inches (701 mm) deep with a 10 in (254 mm) flange, weighing 129 pounds per foot (192 kg/m) — that is what the "129" 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 | 27.6 in (701 mm) |
| Flange width bf | 10 in (254 mm) |
| Web thickness tw | 0.61 in (15.5 mm) |
| Flange thickness tf | 1.1 in (27.9 mm) |
Weight & Cross-Section
| Weight per foot | 129 lb/ft (192 kg/m) |
| 20 ft bar | 2,580 lb |
| 40 ft bar | 5,160 lb |
| Area A | 37.8 in² (243.9 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 4,760 in⁴ (198,125 cm⁴) |
| Section modulus Sx | 345 in³ (5,654 cm³) |
| Radius of gyration rx | 11.2 in |
| Moment of inertia Iy | 184 in⁴ (7,659 cm⁴) |
| Section modulus Sy | 36.8 in³ (603 cm³) |
| Radius of gyration ry | 2.21 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W27x114 | 27.3 × 10.1 | 114 | 4,080 | 299 | −12 % | −14 % |
| W27x129 (this page) | 27.6 × 10 | 129 | 4,760 | 345 | — | — |
| W27x146 | 27.4 × 14 | 146 | 5,660 | 414 | +13 % | +19 % |
Deflection example
A simply supported W27x129 spanning 44 ft with a 10 kip point load at midspan deflects 0.22 in (E = 29,000 ksi, Ix = 4,760 in⁴). The L/360 serviceability limit for this span is 1.47 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W27x129 beam weigh?
W27x129 weighs 129 pounds per foot (192 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 2,580 lb and a 40 ft bar 5,160 lb.
What are the dimensions of a W27x129?
W27x129 is 27.6 in (701 mm) deep with a 10 in (254 mm) wide flange. The web is 0.61 in thick and the flanges are 1.1 in thick. Note the actual depth differs from the nominal W27 label — always design with the actual value.
What are the dimensions of a W27x129 in mm?
W27x129 is 701 mm deep with a 254 mm wide flange; the web is 15.5 mm and the flange 27.9 mm thick. In metric section properties: Ix = 198,125 cm⁴, Sx = 5,654 cm³.
How much does a W27x129 weigh in kg?
192 kg per meter. A 6 m bar weighs 1,152 kg and a 12 m bar 2,304 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W27x129?
About the strong axis, Ix = 4,760 in⁴ (198,125 cm⁴) with section modulus Sx = 345 in³. About the weak axis, Iy = 184 in⁴ and Sy = 36.8 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W27x129 or W27x146 — what does one size up change?
W27x146 is about 13% heavier (146 vs 129 lb/ft) but about 19% stiffer (Ix 5,660 vs 4,760 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