W24×229 Steel Beam
A W24×229 is a wide flange steel beam 26 inches deep with 13.1-inch flanges, weighing 229 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 2,531 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 749 kips.
Design a W24×229 beam Opens a 39 ft span in the free beam designer.
W24×229 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 26.0 in |
| Flange width, bf | 13.1 in |
| Flange thickness, tf | 1.73 in |
| Web thickness, tw | 0.960 in |
| Distance to web toe of fillet, kdes | 2.23 in |
| Distance between flange centroids, ho | 24.27 in |
| Cross-sectional area, A | 67.2 in2 |
| Weight | 229 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W24×229 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 7650 in4 | 651 in4 |
| Elastic section modulus, S | 588 in3 | 99.4 in3 |
| Plastic section modulus, Z | 675 in3 | 154 in3 |
| Radius of gyration, r | 10.7 in | 3.11 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 51.3 in4 |
| Warping constant, Cw | 96100 in6 |
| Effective radius of gyration, rts | 3.67 in |
| Flange slenderness, bf/2tf | 3.79 |
| Web slenderness, h/tw | 22.5 |
W24×229 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 = 2,531 kip-ft | Mn/Ω = 1,684 kip-ft |
| Shear | φVn = 749 kips | Vn/Ω = 499 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 11.0 ft between braces it keeps its full strength; past Lr = 45.2 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 2,531 kip-ft | 1,684 kip-ft |
| 10 ft | 2,531 kip-ft | 1,684 kip-ft |
| 11.0 ft (Lp) | 2,531 kip-ft | 1,684 kip-ft |
| 20 ft | 2,271 kip-ft | 1,511 kip-ft |
| 30 ft | 1,982 kip-ft | 1,319 kip-ft |
| 40 ft | 1,693 kip-ft | 1,126 kip-ft |
| 45.2 ft (Lr) | 1,542 kip-ft | 1,026 kip-ft |
| 50 ft | 1,375 kip-ft | 915 kip-ft |
| 60 ft | 1,125 kip-ft | 749 kip-ft |
| 70 ft | 954 kip-ft | 635 kip-ft |
| 80 ft | 828 kip-ft | 551 kip-ft |
| 90 ft | 732 kip-ft | 487 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.
W24×229 load table by span
The largest uniform load a simply supported W24×229 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 0.229 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 13 ft | 115.2* | 76.8* | 149.6 | 224.4 |
| 15 ft | 90.0 | 59.9 | 97.4 | 146.1 |
| 17 ft | 70.1 | 46.6 | 66.9 | 100.3 |
| 19 ft | 56.1 | 37.3 | 47.9 | 71.9 |
| 21 ft | 45.9 | 30.6 | 35.5 | 53.2 |
| 23 ft | 38.3 | 25.5 | 27.0 | 40.5 |
| 25 ft | 32.4 | 21.6 | 21.0 | 31.6 |
| 27 ft | 27.8 | 18.5 | 16.7 | 25.0 |
| 29 ft | 24.1 | 16.0 | 13.5 | 20.2 |
| 31 ft | 21.1 | 14.0 | 11.0 | 16.5 |
| 33 ft | 18.6 | 12.4 | 9.15 | 13.7 |
| 35 ft | 16.5 | 11.0 | 7.67 | 11.5 |
| 37 ft | 14.8 | 9.84 | 6.49 | 9.73 |
| 39 ft | 13.3 | 8.86 | 5.54 | 8.31 |
| 41 ft | 12.0 | 8.01 | 4.77 | 7.15 |
| 43 ft | 11.0 | 7.29 | 4.13 | 6.20 |
| 45 ft | 10.0 | 6.65 | 3.61 | 5.41 |
| 47 ft | 9.17 | 6.10 | 3.17 | 4.75 |
| 49 ft | 8.43 | 5.61 | 2.79 | 4.19 |
| 51 ft | 7.79 | 5.18 | 2.48 | 3.72 |
| 53 ft | 7.21 | 4.80 | 2.21 | 3.31 |
| 55 ft | 6.69 | 4.45 | 1.98 | 2.96 |
| 57 ft | 6.23 | 4.15 | 1.77 | 2.66 |
| 59 ft | 5.82 | 3.87 | 1.60 | 2.40 |
| 61 ft | 5.44 | 3.62 | 1.45 | 2.17 |
| 63 ft | 5.10 | 3.39 | 1.31 | 1.97 |
| 65 ft | 4.79 | 3.19 | 1.20 | 1.80 |
- 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 39 ft span, a W24×229 carries a factored load of 13.3 kips per foot (LRFD) or an allowable load of 8.86 kips per foot (ASD). A live load of 5.54 kips per foot would deflect it span/360, which is 1.30 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.
W24×229 questions
What does W24×229 mean?
W means a wide flange shape. 24 is its nominal depth in inches (the actual depth is 26.0 in) and 229 is its weight in pounds per foot.
How much does a W24×229 weigh?
229 pounds per foot, so a 20 ft W24×229 weighs about 4,580 pounds.
How far can a W24×229 span?
It depends on the load. Braced along its length, it carries 115.2 kips per foot of factored load at 13 ft and 4.79 kips per foot at 65 ft; the load table has the spans in between. Floor beams are often 39 to 52 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W24×229 a compact section?
Yes. Its flanges (bf/2tf = 3.79) and web (h/tw = 22.5) are both compact for bending in 50 ksi steel.