W30×357 Steel Beam
A W30×357 is a wide flange steel beam 32.8 inches deep with 15.5-inch flanges, weighing 357 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 4,950 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,220 kips.
Design a W30×357 beam Opens a 50 ft span in the free beam designer.
W30×357 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 32.8 in |
| Flange width, bf | 15.5 in |
| Flange thickness, tf | 2.24 in |
| Web thickness, tw | 1.24 in |
| Distance to web toe of fillet, kdes | 3.03 in |
| Distance between flange centroids, ho | 30.56 in |
| Cross-sectional area, A | 105 in2 |
| Weight | 357 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W30×357 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 18700 in4 | 1390 in4 |
| Elastic section modulus, S | 1140 in3 | 179 in3 |
| Plastic section modulus, Z | 1320 in3 | 279 in3 |
| Radius of gyration, r | 13.3 in | 3.64 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 134 in4 |
| Warping constant, Cw | 324000 in6 |
| Effective radius of gyration, rts | 4.31 in |
| Flange slenderness, bf/2tf | 3.45 |
| Web slenderness, h/tw | 21.6 |
W30×357 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 = 4,950 kip-ft | Mn/Ω = 3,293 kip-ft |
| Shear | φVn = 1,220 kips | Vn/Ω = 813 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 12.9 ft between braces it keeps its full strength; past Lr = 54.5 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 4,950 kip-ft | 3,293 kip-ft |
| 10 ft | 4,950 kip-ft | 3,293 kip-ft |
| 12.9 ft (Lp) | 4,950 kip-ft | 3,293 kip-ft |
| 20 ft | 4,614 kip-ft | 3,070 kip-ft |
| 30 ft | 4,145 kip-ft | 2,758 kip-ft |
| 40 ft | 3,675 kip-ft | 2,445 kip-ft |
| 50 ft | 3,205 kip-ft | 2,133 kip-ft |
| 54.5 ft (Lr) | 2,990 kip-ft | 1,990 kip-ft |
| 60 ft | 2,688 kip-ft | 1,788 kip-ft |
| 70 ft | 2,271 kip-ft | 1,511 kip-ft |
| 80 ft | 1,968 kip-ft | 1,309 kip-ft |
| 90 ft | 1,738 kip-ft | 1,156 kip-ft |
| 100 ft | 1,557 kip-ft | 1,036 kip-ft |
| 110 ft | 1,410 kip-ft | 938 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.
W30×357 load table by span
The largest uniform load a simply supported W30×357 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 0.357 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 16 ft | 152.5* | 101.7* | 196.1 | 294.2 |
| 18 ft | 122.2 | 81.3 | 137.8 | 206.6 |
| 20 ft | 99.0 | 65.9 | 100.4 | 150.6 |
| 22 ft | 81.8 | 54.4 | 75.5 | 113.2 |
| 24 ft | 68.8 | 45.7 | 58.1 | 87.2 |
| 26 ft | 58.6 | 39.0 | 45.7 | 68.6 |
| 28 ft | 50.5 | 33.6 | 36.6 | 54.9 |
| 30 ft | 44.0 | 29.3 | 29.8 | 44.6 |
| 32 ft | 38.7 | 25.7 | 24.5 | 36.8 |
| 34 ft | 34.3 | 22.8 | 20.4 | 30.7 |
| 36 ft | 30.6 | 20.3 | 17.2 | 25.8 |
| 38 ft | 27.4 | 18.2 | 14.6 | 22.0 |
| 40 ft | 24.8 | 16.5 | 12.6 | 18.8 |
| 42 ft | 22.4 | 14.9 | 10.8 | 16.3 |
| 44 ft | 20.5 | 13.6 | 9.43 | 14.1 |
| 46 ft | 18.7 | 12.5 | 8.25 | 12.4 |
| 48 ft | 17.2 | 11.4 | 7.26 | 10.9 |
| 50 ft | 15.8 | 10.5 | 6.43 | 9.64 |
| 52 ft | 14.6 | 9.74 | 5.71 | 8.57 |
| 54 ft | 13.6 | 9.04 | 5.10 | 7.65 |
| 56 ft | 12.6 | 8.40 | 4.57 | 6.86 |
| 58 ft | 11.8 | 7.83 | 4.12 | 6.18 |
| 60 ft | 11.0 | 7.32 | 3.72 | 5.58 |
| 62 ft | 10.3 | 6.85 | 3.37 | 5.06 |
| 64 ft | 9.67 | 6.43 | 3.06 | 4.60 |
| 66 ft | 9.09 | 6.05 | 2.79 | 4.19 |
| 68 ft | 8.56 | 5.70 | 2.56 | 3.83 |
| 70 ft | 8.08 | 5.38 | 2.34 | 3.51 |
| 72 ft | 7.64 | 5.08 | 2.15 | 3.23 |
| 74 ft | 7.23 | 4.81 | 1.98 | 2.97 |
| 76 ft | 6.86 | 4.56 | 1.83 | 2.75 |
| 78 ft | 6.51 | 4.33 | 1.69 | 2.54 |
| 80 ft | 6.19 | 4.12 | 1.57 | 2.35 |
| 82 ft | 5.89 | 3.92 | 1.46 | 2.19 |
- 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 50 ft span, a W30×357 carries a factored load of 15.8 kips per foot (LRFD) or an allowable load of 10.5 kips per foot (ASD). A live load of 6.43 kips per foot would deflect it span/360, which is 1.67 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.
W30×357 questions
What does W30×357 mean?
W means a wide flange shape. 30 is its nominal depth in inches (the actual depth is 32.8 in) and 357 is its weight in pounds per foot.
How much does a W30×357 weigh?
357 pounds per foot, so a 20 ft W30×357 weighs about 7,140 pounds.
How far can a W30×357 span?
It depends on the load. Braced along its length, it carries 152.5 kips per foot of factored load at 16 ft and 5.89 kips per foot at 82 ft; the load table has the spans in between. Floor beams are often 49 to 66 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W30×357 a compact section?
Yes. Its flanges (bf/2tf = 3.45) and web (h/tw = 21.6) are both compact for bending in 50 ksi steel.