W27×336 Steel Beam
A W27×336 is a wide flange steel beam 30 inches deep with 14.6-inch flanges, weighing 336 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 4,238 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,134 kips.
Design a W27×336 beam Opens a 45 ft span in the free beam designer.
W27×336 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 30.0 in |
| Flange width, bf | 14.6 in |
| Flange thickness, tf | 2.28 in |
| Web thickness, tw | 1.26 in |
| Distance to web toe of fillet, kdes | 3.07 in |
| Distance between flange centroids, ho | 27.72 in |
| Cross-sectional area, A | 98.9 in2 |
| Weight | 336 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W27×336 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 14600 in4 | 1180 in4 |
| Elastic section modulus, S | 972 in3 | 162 in3 |
| Plastic section modulus, Z | 1130 in3 | 252 in3 |
| Radius of gyration, r | 12.1 in | 3.45 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 131 in4 |
| Warping constant, Cw | 226000 in6 |
| Effective radius of gyration, rts | 4.10 in |
| Flange slenderness, bf/2tf | 3.19 |
| Web slenderness, h/tw | 18.9 |
W27×336 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 = 4,238 kip-ft | Mn/Ω = 2,819 kip-ft |
| Shear | φVn = 1,134 kips | Vn/Ω = 756 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 12.2 ft between braces it keeps its full strength; past Lr = 57.0 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 4,238 kip-ft | 2,819 kip-ft |
| 10 ft | 4,238 kip-ft | 2,819 kip-ft |
| 12.2 ft (Lp) | 4,237 kip-ft | 2,819 kip-ft |
| 20 ft | 3,943 kip-ft | 2,624 kip-ft |
| 30 ft | 3,567 kip-ft | 2,373 kip-ft |
| 40 ft | 3,190 kip-ft | 2,122 kip-ft |
| 50 ft | 2,813 kip-ft | 1,872 kip-ft |
| 57.0 ft (Lr) | 2,552 kip-ft | 1,698 kip-ft |
| 60 ft | 2,410 kip-ft | 1,603 kip-ft |
| 70 ft | 2,044 kip-ft | 1,360 kip-ft |
| 80 ft | 1,776 kip-ft | 1,182 kip-ft |
| 90 ft | 1,571 kip-ft | 1,045 kip-ft |
| 100 ft | 1,409 kip-ft | 938 kip-ft |
| 110 ft | 1,278 kip-ft | 850 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.
W27×336 load table by span
The largest uniform load a simply supported W27×336 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 0.336 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 15 ft | 150.7 | 100.2 | 185.9 | 278.8 |
| 17 ft | 117.3 | 78.0 | 127.7 | 191.5 |
| 19 ft | 93.9 | 62.5 | 91.5 | 137.2 |
| 21 ft | 76.9 | 51.1 | 67.7 | 101.6 |
| 23 ft | 64.1 | 42.6 | 51.6 | 77.3 |
| 25 ft | 54.2 | 36.1 | 40.1 | 60.2 |
| 27 ft | 46.5 | 30.9 | 31.9 | 47.8 |
| 29 ft | 40.3 | 26.8 | 25.7 | 38.6 |
| 31 ft | 35.3 | 23.5 | 21.1 | 31.6 |
| 33 ft | 31.1 | 20.7 | 17.5 | 26.2 |
| 35 ft | 27.7 | 18.4 | 14.6 | 21.9 |
| 37 ft | 24.8 | 16.5 | 12.4 | 18.6 |
| 39 ft | 22.3 | 14.8 | 10.6 | 15.9 |
| 41 ft | 20.2 | 13.4 | 9.10 | 13.7 |
| 43 ft | 18.3 | 12.2 | 7.89 | 11.8 |
| 45 ft | 16.7 | 11.1 | 6.88 | 10.3 |
| 47 ft | 15.3 | 10.2 | 6.04 | 9.06 |
| 49 ft | 14.1 | 9.39 | 5.33 | 8.00 |
| 51 ft | 13.0 | 8.67 | 4.73 | 7.09 |
| 53 ft | 12.1 | 8.03 | 4.21 | 6.32 |
| 55 ft | 11.2 | 7.46 | 3.77 | 5.66 |
| 57 ft | 10.4 | 6.94 | 3.39 | 5.08 |
| 59 ft | 9.74 | 6.48 | 3.05 | 4.58 |
| 61 ft | 9.11 | 6.06 | 2.76 | 4.15 |
| 63 ft | 8.54 | 5.68 | 2.51 | 3.76 |
| 65 ft | 8.02 | 5.34 | 2.28 | 3.43 |
| 67 ft | 7.55 | 5.02 | 2.09 | 3.13 |
| 69 ft | 7.12 | 4.74 | 1.91 | 2.86 |
| 71 ft | 6.72 | 4.47 | 1.75 | 2.63 |
| 73 ft | 6.36 | 4.23 | 1.61 | 2.42 |
| 75 ft | 6.03 | 4.01 | 1.49 | 2.23 |
- 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 W27×336 carries a factored load of 16.7 kips per foot (LRFD) or an allowable load of 11.1 kips per foot (ASD). A live load of 6.88 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.
W27×336 questions
What does W27×336 mean?
W means a wide flange shape. 27 is its nominal depth in inches (the actual depth is 30.0 in) and 336 is its weight in pounds per foot.
How much does a W27×336 weigh?
336 pounds per foot, so a 20 ft W27×336 weighs about 6,720 pounds.
How far can a W27×336 span?
It depends on the load. Braced along its length, it carries 150.7 kips per foot of factored load at 15 ft and 6.03 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 W27×336 a compact section?
Yes. Its flanges (bf/2tf = 3.19) and web (h/tw = 18.9) are both compact for bending in 50 ksi steel.