W33×152 Steel Beam
A W33×152 is a wide flange steel beam 33.5 inches deep with 11.6-inch flanges, weighing 152 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 2,096 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 638 kips.
Design a W33×152 beam Opens a 51 ft span in the free beam designer.
W33×152 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 33.5 in |
| Flange width, bf | 11.6 in |
| Flange thickness, tf | 1.06 in |
| Web thickness, tw | 0.635 in |
| Distance to web toe of fillet, kdes | 1.76 in |
| Distance between flange centroids, ho | 32.44 in |
| Cross-sectional area, A | 44.8 in2 |
| Weight | 152 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W33×152 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 8160 in4 | 273 in4 |
| Elastic section modulus, S | 487 in3 | 47.2 in3 |
| Plastic section modulus, Z | 559 in3 | 73.9 in3 |
| Radius of gyration, r | 13.5 in | 2.47 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 12.4 in4 |
| Warping constant, Cw | 71700 in6 |
| Effective radius of gyration, rts | 3.01 in |
| Flange slenderness, bf/2tf | 5.48 |
| Web slenderness, h/tw | 47.2 |
W33×152 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 = 2,096 kip-ft | Mn/Ω = 1,395 kip-ft |
| Shear | φVn = 638 kips | Vn/Ω = 425 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 8.7 ft between braces it keeps its full strength; past Lr = 25.7 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 2,096 kip-ft | 1,395 kip-ft |
| 5 ft | 2,096 kip-ft | 1,395 kip-ft |
| 8.7 ft (Lp) | 2,096 kip-ft | 1,395 kip-ft |
| 10 ft | 2,035 kip-ft | 1,354 kip-ft |
| 15 ft | 1,794 kip-ft | 1,194 kip-ft |
| 20 ft | 1,554 kip-ft | 1,034 kip-ft |
| 25 ft | 1,313 kip-ft | 874 kip-ft |
| 25.7 ft (Lr) | 1,277 kip-ft | 849 kip-ft |
| 30 ft | 1,003 kip-ft | 667 kip-ft |
| 35 ft | 797 kip-ft | 530 kip-ft |
| 40 ft | 659 kip-ft | 438 kip-ft |
| 45 ft | 561 kip-ft | 373 kip-ft |
| 50 ft | 488 kip-ft | 325 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.
W33×152 load table by span
The largest uniform load a simply supported W33×152 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 0.152 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 17 ft | 58.0 | 38.6 | 71.4 | 107.0 |
| 19 ft | 46.5 | 30.9 | 51.1 | 76.7 |
| 21 ft | 38.0 | 25.3 | 37.9 | 56.8 |
| 23 ft | 31.7 | 21.1 | 28.8 | 43.2 |
| 25 ft | 26.8 | 17.9 | 22.4 | 33.7 |
| 27 ft | 23.0 | 15.3 | 17.8 | 26.7 |
| 29 ft | 19.9 | 13.3 | 14.4 | 21.6 |
| 31 ft | 17.5 | 11.6 | 11.8 | 17.7 |
| 33 ft | 15.4 | 10.2 | 9.76 | 14.6 |
| 35 ft | 13.7 | 9.11 | 8.18 | 12.3 |
| 37 ft | 12.2 | 8.15 | 6.92 | 10.4 |
| 39 ft | 11.0 | 7.34 | 5.91 | 8.87 |
| 41 ft | 9.98 | 6.64 | 5.09 | 7.63 |
| 43 ft | 9.07 | 6.03 | 4.41 | 6.61 |
| 45 ft | 8.28 | 5.51 | 3.85 | 5.77 |
| 47 ft | 7.59 | 5.05 | 3.38 | 5.07 |
| 49 ft | 6.98 | 4.65 | 2.98 | 4.47 |
| 51 ft | 6.45 | 4.29 | 2.64 | 3.96 |
| 53 ft | 5.97 | 3.97 | 2.35 | 3.53 |
| 55 ft | 5.54 | 3.69 | 2.11 | 3.16 |
| 57 ft | 5.16 | 3.43 | 1.89 | 2.84 |
| 59 ft | 4.82 | 3.21 | 1.71 | 2.56 |
| 61 ft | 4.51 | 3.00 | 1.54 | 2.32 |
| 63 ft | 4.23 | 2.81 | 1.40 | 2.10 |
| 65 ft | 3.97 | 2.64 | 1.28 | 1.91 |
| 67 ft | 3.74 | 2.49 | 1.17 | 1.75 |
| 69 ft | 3.52 | 2.34 | 1.07 | 1.60 |
| 71 ft | 3.33 | 2.21 | 0.98 | 1.47 |
| 73 ft | 3.15 | 2.09 | 0.90 | 1.35 |
| 75 ft | 2.98 | 1.98 | 0.83 | 1.25 |
| 77 ft | 2.83 | 1.88 | 0.77 | 1.15 |
| 79 ft | 2.69 | 1.79 | 0.71 | 1.07 |
| 81 ft | 2.56 | 1.70 | 0.66 | 0.99 |
| 83 ft | 2.43 | 1.62 | 0.61 | 0.92 |
- 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 51 ft span, a W33×152 carries a factored load of 6.45 kips per foot (LRFD) or an allowable load of 4.29 kips per foot (ASD). A live load of 2.64 kips per foot would deflect it span/360, which is 1.70 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.
W33×152 questions
What does W33×152 mean?
W means a wide flange shape. 33 is its nominal depth in inches (the actual depth is 33.5 in) and 152 is its weight in pounds per foot.
How much does a W33×152 weigh?
152 pounds per foot, so a 20 ft W33×152 weighs about 3,040 pounds.
How far can a W33×152 span?
It depends on the load. Braced along its length, it carries 58.0 kips per foot of factored load at 17 ft and 2.43 kips per foot at 83 ft; the load table has the spans in between. Floor beams are often 50 to 67 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W33×152 a compact section?
Yes. Its flanges (bf/2tf = 5.48) and web (h/tw = 47.2) are both compact for bending in 50 ksi steel.