W30×326 Steel Beam
A W30×326 is a wide flange steel beam 32.4 inches deep with 15.4-inch flanges, weighing 326 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 4,463 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,108 kips.
Design a W30×326 beam Opens a 48 ft span in the free beam designer.
W30×326 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 32.4 in |
| Flange width, bf | 15.4 in |
| Flange thickness, tf | 2.05 in |
| Web thickness, tw | 1.14 in |
| Distance to web toe of fillet, kdes | 2.84 in |
| Distance between flange centroids, ho | 30.35 in |
| Cross-sectional area, A | 95.8 in2 |
| Weight | 326 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W30×326 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 16800 in4 | 1240 in4 |
| Elastic section modulus, S | 1040 in3 | 162 in3 |
| Plastic section modulus, Z | 1190 in3 | 252 in3 |
| Radius of gyration, r | 13.2 in | 3.60 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 103 in4 |
| Warping constant, Cw | 287000 in6 |
| Effective radius of gyration, rts | 4.26 in |
| Flange slenderness, bf/2tf | 3.75 |
| Web slenderness, h/tw | 23.4 |
W30×326 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 = 4,463 kip-ft | Mn/Ω = 2,969 kip-ft |
| Shear | φVn = 1,108 kips | Vn/Ω = 739 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 12.7 ft between braces it keeps its full strength; past Lr = 50.6 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 4,463 kip-ft | 2,969 kip-ft |
| 10 ft | 4,463 kip-ft | 2,969 kip-ft |
| 12.7 ft (Lp) | 4,462 kip-ft | 2,969 kip-ft |
| 20 ft | 4,130 kip-ft | 2,748 kip-ft |
| 30 ft | 3,672 kip-ft | 2,443 kip-ft |
| 40 ft | 3,215 kip-ft | 2,139 kip-ft |
| 50 ft | 2,758 kip-ft | 1,835 kip-ft |
| 50.6 ft (Lr) | 2,730 kip-ft | 1,816 kip-ft |
| 60 ft | 2,247 kip-ft | 1,495 kip-ft |
| 70 ft | 1,895 kip-ft | 1,261 kip-ft |
| 80 ft | 1,640 kip-ft | 1,091 kip-ft |
| 90 ft | 1,447 kip-ft | 963 kip-ft |
| 100 ft | 1,295 kip-ft | 862 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.
W30×326 load table by span
The largest uniform load a simply supported W30×326 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 0.326 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 16 ft | 138.5* | 92.3* | 176.2 | 264.3 |
| 18 ft | 110.2 | 73.3 | 123.8 | 185.6 |
| 20 ft | 89.3 | 59.4 | 90.2 | 135.3 |
| 22 ft | 73.8 | 49.1 | 67.8 | 101.7 |
| 24 ft | 62.0 | 41.2 | 52.2 | 78.3 |
| 26 ft | 52.8 | 35.1 | 41.1 | 61.6 |
| 28 ft | 45.5 | 30.3 | 32.9 | 49.3 |
| 30 ft | 39.7 | 26.4 | 26.7 | 40.1 |
| 32 ft | 34.9 | 23.2 | 22.0 | 33.0 |
| 34 ft | 30.9 | 20.5 | 18.4 | 27.5 |
| 36 ft | 27.5 | 18.3 | 15.5 | 23.2 |
| 38 ft | 24.7 | 16.4 | 13.2 | 19.7 |
| 40 ft | 22.3 | 14.8 | 11.3 | 16.9 |
| 42 ft | 20.2 | 13.5 | 9.74 | 14.6 |
| 44 ft | 18.4 | 12.3 | 8.47 | 12.7 |
| 46 ft | 16.9 | 11.2 | 7.42 | 11.1 |
| 48 ft | 15.5 | 10.3 | 6.53 | 9.79 |
| 50 ft | 14.3 | 9.50 | 5.77 | 8.66 |
| 52 ft | 13.2 | 8.78 | 5.13 | 7.70 |
| 54 ft | 12.2 | 8.15 | 4.58 | 6.88 |
| 56 ft | 11.4 | 7.57 | 4.11 | 6.16 |
| 58 ft | 10.6 | 7.06 | 3.70 | 5.55 |
| 60 ft | 9.92 | 6.60 | 3.34 | 5.01 |
| 62 ft | 9.29 | 6.18 | 3.03 | 4.54 |
| 64 ft | 8.72 | 5.80 | 2.75 | 4.13 |
| 66 ft | 8.20 | 5.45 | 2.51 | 3.77 |
| 68 ft | 7.72 | 5.14 | 2.30 | 3.44 |
| 70 ft | 7.29 | 4.85 | 2.10 | 3.16 |
| 72 ft | 6.89 | 4.58 | 1.93 | 2.90 |
| 74 ft | 6.52 | 4.34 | 1.78 | 2.67 |
| 76 ft | 6.18 | 4.11 | 1.64 | 2.47 |
| 78 ft | 5.87 | 3.90 | 1.52 | 2.28 |
| 80 ft | 5.58 | 3.71 | 1.41 | 2.11 |
- 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 48 ft span, a W30×326 carries a factored load of 15.5 kips per foot (LRFD) or an allowable load of 10.3 kips per foot (ASD). A live load of 6.53 kips per foot would deflect it span/360, which is 1.60 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.
W30×326 questions
What does W30×326 mean?
W means a wide flange shape. 30 is its nominal depth in inches (the actual depth is 32.4 in) and 326 is its weight in pounds per foot.
How much does a W30×326 weigh?
326 pounds per foot, so a 20 ft W30×326 weighs about 6,520 pounds.
How far can a W30×326 span?
It depends on the load. Braced along its length, it carries 138.5 kips per foot of factored load at 16 ft and 5.58 kips per foot at 80 ft; the load table has the spans in between. Floor beams are often 49 to 65 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W30×326 a compact section?
Yes. Its flanges (bf/2tf = 3.75) and web (h/tw = 23.4) are both compact for bending in 50 ksi steel.