W30×116 Steel Beam
A W30×116 is a wide flange steel beam 30 inches deep with 10.5-inch flanges, weighing 116 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 1,418 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 508 kips.
Design a W30×116 beam Opens a 45 ft span in the free beam designer.
W30×116 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 30.0 in |
| Flange width, bf | 10.5 in |
| Flange thickness, tf | 0.850 in |
| Web thickness, tw | 0.565 in |
| Distance to web toe of fillet, kdes | 1.50 in |
| Distance between flange centroids, ho | 29.15 in |
| Cross-sectional area, A | 34.2 in2 |
| Weight | 116 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W30×116 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 4930 in4 | 164 in4 |
| Elastic section modulus, S | 329 in3 | 31.3 in3 |
| Plastic section modulus, Z | 378 in3 | 49.2 in3 |
| Radius of gyration, r | 12.0 in | 2.19 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 6.43 in4 |
| Warping constant, Cw | 34900 in6 |
| Effective radius of gyration, rts | 2.70 in |
| Flange slenderness, bf/2tf | 6.17 |
| Web slenderness, h/tw | 47.8 |
W30×116 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 = 1,418 kip-ft | Mn/Ω = 943 kip-ft |
| Shear | φVn = 508 kips | Vn/Ω = 339 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 7.7 ft between braces it keeps its full strength; past Lr = 22.6 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 1,418 kip-ft | 943 kip-ft |
| 5 ft | 1,418 kip-ft | 943 kip-ft |
| 7.7 ft (Lp) | 1,417 kip-ft | 943 kip-ft |
| 10 ft | 1,333 kip-ft | 887 kip-ft |
| 15 ft | 1,147 kip-ft | 763 kip-ft |
| 20 ft | 961 kip-ft | 639 kip-ft |
| 22.6 ft (Lr) | 864 kip-ft | 575 kip-ft |
| 25 ft | 732 kip-ft | 487 kip-ft |
| 30 ft | 551 kip-ft | 366 kip-ft |
| 35 ft | 439 kip-ft | 292 kip-ft |
| 40 ft | 363 kip-ft | 242 kip-ft |
| 45 ft | 310 kip-ft | 206 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.
W30×116 load table by span
The largest uniform load a simply supported W30×116 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 0.116 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 15 ft | 50.4 | 33.5 | 62.8 | 94.1 |
| 17 ft | 39.2 | 26.1 | 43.1 | 64.7 |
| 19 ft | 31.4 | 20.9 | 30.9 | 46.3 |
| 21 ft | 25.7 | 17.1 | 22.9 | 34.3 |
| 23 ft | 21.4 | 14.3 | 17.4 | 26.1 |
| 25 ft | 18.1 | 12.1 | 13.6 | 20.3 |
| 27 ft | 15.6 | 10.3 | 10.8 | 16.1 |
| 29 ft | 13.5 | 8.97 | 8.68 | 13.0 |
| 31 ft | 11.8 | 7.85 | 7.11 | 10.7 |
| 33 ft | 10.4 | 6.93 | 5.89 | 8.84 |
| 35 ft | 9.26 | 6.16 | 4.94 | 7.41 |
| 37 ft | 8.28 | 5.51 | 4.18 | 6.27 |
| 39 ft | 7.46 | 4.96 | 3.57 | 5.36 |
| 41 ft | 6.75 | 4.49 | 3.07 | 4.61 |
| 43 ft | 6.13 | 4.08 | 2.66 | 4.00 |
| 45 ft | 5.60 | 3.73 | 2.32 | 3.49 |
| 47 ft | 5.13 | 3.42 | 2.04 | 3.06 |
| 49 ft | 4.72 | 3.14 | 1.80 | 2.70 |
| 51 ft | 4.36 | 2.90 | 1.60 | 2.40 |
| 53 ft | 4.04 | 2.69 | 1.42 | 2.13 |
| 55 ft | 3.75 | 2.49 | 1.27 | 1.91 |
| 57 ft | 3.49 | 2.32 | 1.14 | 1.72 |
| 59 ft | 3.26 | 2.17 | 1.03 | 1.55 |
| 61 ft | 3.05 | 2.03 | 0.93 | 1.40 |
| 63 ft | 2.86 | 1.90 | 0.85 | 1.27 |
| 65 ft | 2.68 | 1.79 | 0.77 | 1.16 |
| 67 ft | 2.53 | 1.68 | 0.70 | 1.06 |
| 69 ft | 2.38 | 1.58 | 0.64 | 0.97 |
| 71 ft | 2.25 | 1.50 | 0.59 | 0.89 |
| 73 ft | 2.13 | 1.42 | 0.54 | 0.82 |
| 75 ft | 2.02 | 1.34 | 0.50 | 0.75 |
- 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 45 ft span, a W30×116 carries a factored load of 5.60 kips per foot (LRFD) or an allowable load of 3.73 kips per foot (ASD). A live load of 2.32 kips per foot would deflect it span/360, which is 1.50 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.
W30×116 questions
What does W30×116 mean?
W means a wide flange shape. 30 is its nominal depth in inches (the actual depth is 30.0 in) and 116 is its weight in pounds per foot.
How much does a W30×116 weigh?
116 pounds per foot, so a 20 ft W30×116 weighs about 2,320 pounds.
How far can a W30×116 span?
It depends on the load. Braced along its length, it carries 50.4 kips per foot of factored load at 15 ft and 2.02 kips per foot at 75 ft; the load table has the spans in between. Floor beams are often 45 to 60 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W30×116 a compact section?
Yes. Its flanges (bf/2tf = 6.17) and web (h/tw = 47.8) are both compact for bending in 50 ksi steel.