W33×354 Steel Beam
A W33×354 is a wide flange steel beam 35.6 inches deep with 16.1-inch flanges, weighing 354 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 5,325 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,239 kips.
Design a W33×354 beam Opens a 54 ft span in the free beam designer.
W33×354 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 35.6 in |
| Flange width, bf | 16.1 in |
| Flange thickness, tf | 2.09 in |
| Web thickness, tw | 1.16 in |
| Distance to web toe of fillet, kdes | 2.88 in |
| Distance between flange centroids, ho | 33.51 in |
| Cross-sectional area, A | 104 in2 |
| Weight | 354 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W33×354 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 22000 in4 | 1460 in4 |
| Elastic section modulus, S | 1240 in3 | 181 in3 |
| Plastic section modulus, Z | 1420 in3 | 282 in3 |
| Radius of gyration, r | 14.5 in | 3.74 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 115 in4 |
| Warping constant, Cw | 408000 in6 |
| Effective radius of gyration, rts | 4.44 in |
| Flange slenderness, bf/2tf | 3.85 |
| Web slenderness, h/tw | 25.7 |
W33×354 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 = 5,325 kip-ft | Mn/Ω = 3,543 kip-ft |
| Shear | φVn = 1,239 kips | Vn/Ω = 826 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 13.2 ft between braces it keeps its full strength; past Lr = 49.8 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 5,325 kip-ft | 3,543 kip-ft |
| 10 ft | 5,325 kip-ft | 3,543 kip-ft |
| 13.2 ft (Lp) | 5,325 kip-ft | 3,543 kip-ft |
| 20 ft | 4,941 kip-ft | 3,287 kip-ft |
| 30 ft | 4,375 kip-ft | 2,911 kip-ft |
| 40 ft | 3,810 kip-ft | 2,535 kip-ft |
| 49.8 ft (Lr) | 3,255 kip-ft | 2,166 kip-ft |
| 50 ft | 3,237 kip-ft | 2,154 kip-ft |
| 60 ft | 2,613 kip-ft | 1,739 kip-ft |
| 70 ft | 2,195 kip-ft | 1,460 kip-ft |
| 80 ft | 1,895 kip-ft | 1,261 kip-ft |
| 90 ft | 1,668 kip-ft | 1,110 kip-ft |
| 100 ft | 1,491 kip-ft | 992 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.
W33×354 load table by span
The largest uniform load a simply supported W33×354 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 0.354 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 18 ft | 131.5 | 87.5 | 162.1 | 243.1 |
| 20 ft | 106.5 | 70.9 | 118.1 | 177.2 |
| 22 ft | 88.0 | 58.6 | 88.8 | 133.1 |
| 24 ft | 74.0 | 49.2 | 68.4 | 102.6 |
| 26 ft | 63.0 | 41.9 | 53.8 | 80.7 |
| 28 ft | 54.3 | 36.2 | 43.1 | 64.6 |
| 30 ft | 47.3 | 31.5 | 35.0 | 52.5 |
| 32 ft | 41.6 | 27.7 | 28.8 | 43.3 |
| 34 ft | 36.9 | 24.5 | 24.0 | 36.1 |
| 36 ft | 32.9 | 21.9 | 20.3 | 30.4 |
| 38 ft | 29.5 | 19.6 | 17.2 | 25.8 |
| 40 ft | 26.6 | 17.7 | 14.8 | 22.2 |
| 42 ft | 24.1 | 16.1 | 12.8 | 19.1 |
| 44 ft | 22.0 | 14.6 | 11.1 | 16.6 |
| 46 ft | 20.1 | 13.4 | 9.71 | 14.6 |
| 48 ft | 18.5 | 12.3 | 8.55 | 12.8 |
| 50 ft | 17.0 | 11.3 | 7.56 | 11.3 |
| 52 ft | 15.8 | 10.5 | 6.72 | 10.1 |
| 54 ft | 14.6 | 9.72 | 6.00 | 9.00 |
| 56 ft | 13.6 | 9.04 | 5.38 | 8.07 |
| 58 ft | 12.7 | 8.43 | 4.84 | 7.27 |
| 60 ft | 11.8 | 7.87 | 4.38 | 6.56 |
| 62 ft | 11.1 | 7.37 | 3.97 | 5.95 |
| 64 ft | 10.4 | 6.92 | 3.61 | 5.41 |
| 66 ft | 9.78 | 6.51 | 3.29 | 4.93 |
| 68 ft | 9.21 | 6.13 | 3.01 | 4.51 |
| 70 ft | 8.69 | 5.78 | 2.76 | 4.13 |
| 72 ft | 8.22 | 5.47 | 2.53 | 3.80 |
| 74 ft | 7.78 | 5.18 | 2.33 | 3.50 |
| 76 ft | 7.38 | 4.91 | 2.15 | 3.23 |
| 78 ft | 7.00 | 4.66 | 1.99 | 2.99 |
| 80 ft | 6.66 | 4.43 | 1.85 | 2.77 |
| 82 ft | 6.34 | 4.22 | 1.71 | 2.57 |
| 84 ft | 6.04 | 4.02 | 1.59 | 2.39 |
| 86 ft | 5.76 | 3.83 | 1.49 | 2.23 |
| 88 ft | 5.50 | 3.66 | 1.39 | 2.08 |
- 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 54 ft span, a W33×354 carries a factored load of 14.6 kips per foot (LRFD) or an allowable load of 9.72 kips per foot (ASD). A live load of 6.00 kips per foot would deflect it span/360, which is 1.80 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.
W33×354 questions
What does W33×354 mean?
W means a wide flange shape. 33 is its nominal depth in inches (the actual depth is 35.6 in) and 354 is its weight in pounds per foot.
How much does a W33×354 weigh?
354 pounds per foot, so a 20 ft W33×354 weighs about 7,080 pounds.
How far can a W33×354 span?
It depends on the load. Braced along its length, it carries 131.5 kips per foot of factored load at 18 ft and 5.50 kips per foot at 88 ft; the load table has the spans in between. Floor beams are often 53 to 71 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W33×354 a compact section?
Yes. Its flanges (bf/2tf = 3.85) and web (h/tw = 25.7) are both compact for bending in 50 ksi steel.