W30x124 — Dimensions, Weight & Section Properties
American wide-flange (W) beam per ASTM A6 / AISC Steel Construction Manual
W30x124 is an American wide-flange beam 30.2 inches (767.1 mm) deep with a 10.5 in (266.7 mm) flange, weighing 124 pounds per foot (184.5 kg/m) — that is what the "124" 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 | 30.2 in (767.1 mm) |
| Flange width bf | 10.5 in (266.7 mm) |
| Web thickness tw | 0.585 in (14.9 mm) |
| Flange thickness tf | 0.93 in (23.6 mm) |
Weight & Cross-Section
| Weight per foot | 124 lb/ft (184.5 kg/m) |
| 20 ft bar | 2,480 lb |
| 40 ft bar | 4,960 lb |
| Area A | 36.5 in² (235.5 cm²) |
Section Properties (strong / weak axis)
| Moment of inertia Ix | 5,360 in⁴ (223,099 cm⁴) |
| Section modulus Sx | 355 in³ (5,817 cm³) |
| Radius of gyration rx | 12.1 in |
| Moment of inertia Iy | 181 in⁴ (7,534 cm⁴) |
| Section modulus Sy | 34.4 in³ (564 cm³) |
| Radius of gyration ry | 2.23 in |
Compared with the neighbouring sizes
| Shape | d × bf (in) | lb/ft | Ix (in⁴) | Sx (in³) | Δ weight | Δ Ix |
|---|---|---|---|---|---|---|
| W30x116 | 30 × 10.5 | 116 | 4,930 | 329 | −6 % | −8 % |
| W30x124 (this page) | 30.2 × 10.5 | 124 | 5,360 | 355 | — | — |
| W30x132 | 30.3 × 10.5 | 132 | 5,770 | 380 | +6 % | +8 % |
Deflection example
A simply supported W30x124 spanning 48 ft with a 10 kip point load at midspan deflects 0.26 in (E = 29,000 ksi, Ix = 5,360 in⁴). The L/360 serviceability limit for this span is 1.6 in — the shape passes this quick check.
Calculate with your own span and load →
Frequently asked questions
How much does a W30x124 beam weigh?
W30x124 weighs 124 pounds per foot (184.5 kg/m). The number after the "x" in the designation is always the weight in lb/ft. A 20 ft bar weighs 2,480 lb and a 40 ft bar 4,960 lb.
What are the dimensions of a W30x124?
W30x124 is 30.2 in (767.1 mm) deep with a 10.5 in (266.7 mm) wide flange. The web is 0.59 in thick and the flanges are 0.93 in thick. Note the actual depth differs from the nominal W30 label — always design with the actual value.
What are the dimensions of a W30x124 in mm?
W30x124 is 767.1 mm deep with a 266.7 mm wide flange; the web is 14.9 mm and the flange 23.6 mm thick. In metric section properties: Ix = 223,099 cm⁴, Sx = 5,817 cm³.
How much does a W30x124 weigh in kg?
184.5 kg per meter. A 6 m bar weighs 1,107 kg and a 12 m bar 2,214 kg — handy when ordering US shapes from metric suppliers.
What is the moment of inertia of a W30x124?
About the strong axis, Ix = 5,360 in⁴ (223,099 cm⁴) with section modulus Sx = 355 in³. About the weak axis, Iy = 181 in⁴ and Sy = 34.4 in³. Use the beam deflection calculator to turn these into deflection and stress for your span and load.
W30x124 or W30x132 — what does one size up change?
W30x132 is about 6% heavier (132 vs 124 lb/ft) but about 8% stiffer (Ix 5,770 vs 5,360 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