W24×146 Steel Beam
A W24×146 is a wide flange steel beam 24.7 inches deep with 12.9-inch flanges, weighing 146 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 1,568 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 482 kips.
Design a W24×146 beam Opens a 38 ft span in the free beam designer.
W24×146 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 24.7 in |
| Flange width, bf | 12.9 in |
| Flange thickness, tf | 1.09 in |
| Web thickness, tw | 0.650 in |
| Distance to web toe of fillet, kdes | 1.59 in |
| Distance between flange centroids, ho | 23.61 in |
| Cross-sectional area, A | 43.0 in2 |
| Weight | 146 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W24×146 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 4580 in4 | 391 in4 |
| Elastic section modulus, S | 371 in3 | 60.5 in3 |
| Plastic section modulus, Z | 418 in3 | 93.2 in3 |
| Radius of gyration, r | 10.3 in | 3.01 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 13.4 in4 |
| Warping constant, Cw | 54600 in6 |
| Effective radius of gyration, rts | 3.53 in |
| Flange slenderness, bf/2tf | 5.92 |
| Web slenderness, h/tw | 33.2 |
W24×146 bending and shear strength
For ASTM A992 steel (Fy = 50 ksi, E = 29,000 ksi) per AISC 360-16. Its flanges and web are compact for bending, so with its compression flange braced it reaches its full plastic moment.
| Strength | LRFD | ASD |
|---|---|---|
| Bending, compression flange braced | φMn = 1,568 kip-ft | Mn/Ω = 1,043 kip-ft |
| Shear | φVn = 482 kips | Vn/Ω = 321 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 10.6 ft between braces it keeps its full strength; past Lr = 33.7 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 1,568 kip-ft | 1,043 kip-ft |
| 10 ft | 1,568 kip-ft | 1,043 kip-ft |
| 10.6 ft (Lp) | 1,568 kip-ft | 1,043 kip-ft |
| 20 ft | 1,326 kip-ft | 882 kip-ft |
| 30 ft | 1,068 kip-ft | 711 kip-ft |
| 33.7 ft (Lr) | 973 kip-ft | 647 kip-ft |
| 40 ft | 771 kip-ft | 513 kip-ft |
| 50 ft | 581 kip-ft | 387 kip-ft |
| 60 ft | 467 kip-ft | 311 kip-ft |
| 70 ft | 392 kip-ft | 261 kip-ft |
A beam with a uniform load between braces has Cb above 1.0 (1.14 for a simple span braced only at its ends), so these values are conservative. The beam designer works out Cb for every segment between braces.
W24×146 load table by span
The largest uniform load a simply supported W24×146 can carry, in kips per foot, with its compression flange braced along its length (by a floor or roof deck, for example). The loads include the beam's own weight of 0.146 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 12 ft | 80.3* | 53.5* | 113.9 | 170.8 |
| 14 ft | 64.0 | 42.6 | 71.7 | 107.6 |
| 16 ft | 49.0 | 32.6 | 48.0 | 72.1 |
| 18 ft | 38.7 | 25.8 | 33.7 | 50.6 |
| 20 ft | 31.3 | 20.9 | 24.6 | 36.9 |
| 22 ft | 25.9 | 17.2 | 18.5 | 27.7 |
| 24 ft | 21.8 | 14.5 | 14.2 | 21.4 |
| 26 ft | 18.6 | 12.3 | 11.2 | 16.8 |
| 28 ft | 16.0 | 10.6 | 8.96 | 13.4 |
| 30 ft | 13.9 | 9.27 | 7.29 | 10.9 |
| 32 ft | 12.2 | 8.15 | 6.00 | 9.01 |
| 34 ft | 10.8 | 7.22 | 5.01 | 7.51 |
| 36 ft | 9.68 | 6.44 | 4.22 | 6.33 |
| 38 ft | 8.68 | 5.78 | 3.59 | 5.38 |
| 40 ft | 7.84 | 5.21 | 3.07 | 4.61 |
| 42 ft | 7.11 | 4.73 | 2.66 | 3.98 |
| 44 ft | 6.48 | 4.31 | 2.31 | 3.46 |
| 46 ft | 5.93 | 3.94 | 2.02 | 3.03 |
| 48 ft | 5.44 | 3.62 | 1.78 | 2.67 |
| 50 ft | 5.02 | 3.34 | 1.57 | 2.36 |
| 52 ft | 4.64 | 3.09 | 1.40 | 2.10 |
| 54 ft | 4.30 | 2.86 | 1.25 | 1.87 |
| 56 ft | 4.00 | 2.66 | 1.12 | 1.68 |
| 58 ft | 3.73 | 2.48 | 1.01 | 1.51 |
| 60 ft | 3.48 | 2.32 | 0.91 | 1.37 |
| 62 ft | 3.26 | 2.17 | 0.83 | 1.24 |
- Factored and allowable loads are limited by bending, or by shear where marked *.
- The deflection columns are the service loads that make the beam sag span/360 or span/240. Compare span/360 with the live load alone and span/240 with dead plus live load, the usual floor limits in IBC Table 1604.3.
Reading the table
At a 38 ft span, a W24×146 carries a factored load of 8.68 kips per foot (LRFD) or an allowable load of 5.78 kips per foot (ASD). A live load of 3.59 kips per foot would deflect it span/360, which is 1.27 in. The beam works if the factored load is under the first number and the live and total loads are under the deflection numbers. For other spans, supports or loads, open it in the beam designer, or follow the steel beam design guide to check one by hand.
W24×146 questions
What does W24×146 mean?
W means a wide flange shape. 24 is its nominal depth in inches (the actual depth is 24.7 in) and 146 is its weight in pounds per foot.
How much does a W24×146 weigh?
146 pounds per foot, so a 20 ft W24×146 weighs about 2,920 pounds.
How far can a W24×146 span?
It depends on the load. Braced along its length, it carries 80.3 kips per foot of factored load at 12 ft and 3.26 kips per foot at 62 ft; the load table has the spans in between. Floor beams are often 37 to 49 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W24×146 a compact section?
Yes. Its flanges (bf/2tf = 5.92) and web (h/tw = 33.2) are both compact for bending in 50 ksi steel.