W36×302 Steel Beam
A W36×302 is a wide flange steel beam 37.3 inches deep with 16.7-inch flanges, weighing 302 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 4,800 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,057 kips.
Design a W36×302 beam Opens a 57 ft span in the free beam designer.
W36×302 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 37.3 in |
| Flange width, bf | 16.7 in |
| Flange thickness, tf | 1.68 in |
| Web thickness, tw | 0.945 in |
| Distance to web toe of fillet, kdes | 2.63 in |
| Distance between flange centroids, ho | 35.62 in |
| Cross-sectional area, A | 88.8 in2 |
| Weight | 302 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W36×302 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 21100 in4 | 1300 in4 |
| Elastic section modulus, S | 1130 in3 | 156 in3 |
| Plastic section modulus, Z | 1280 in3 | 241 in3 |
| Radius of gyration, r | 15.4 in | 3.82 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 64.3 in4 |
| Warping constant, Cw | 412000 in6 |
| Effective radius of gyration, rts | 4.53 in |
| Flange slenderness, bf/2tf | 4.96 |
| Web slenderness, h/tw | 33.9 |
W36×302 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 = 4,800 kip-ft | Mn/Ω = 3,194 kip-ft |
| Shear | φVn = 1,057 kips | Vn/Ω = 705 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 13.5 ft between braces it keeps its full strength; past Lr = 43.6 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 4,800 kip-ft | 3,194 kip-ft |
| 10 ft | 4,800 kip-ft | 3,194 kip-ft |
| 13.5 ft (Lp) | 4,800 kip-ft | 3,194 kip-ft |
| 20 ft | 4,404 kip-ft | 2,930 kip-ft |
| 30 ft | 3,794 kip-ft | 2,525 kip-ft |
| 40 ft | 3,185 kip-ft | 2,119 kip-ft |
| 43.6 ft (Lr) | 2,967 kip-ft | 1,974 kip-ft |
| 50 ft | 2,465 kip-ft | 1,640 kip-ft |
| 60 ft | 1,953 kip-ft | 1,300 kip-ft |
| 70 ft | 1,620 kip-ft | 1,078 kip-ft |
| 80 ft | 1,386 kip-ft | 922 kip-ft |
| 90 ft | 1,212 kip-ft | 806 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.
W36×302 load table by span
The largest uniform load a simply supported W36×302 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 0.302 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 19 ft | 106.4 | 70.8 | 132.2 | 198.2 |
| 21 ft | 87.1 | 57.9 | 97.9 | 146.8 |
| 23 ft | 72.6 | 48.3 | 74.5 | 111.8 |
| 25 ft | 61.4 | 40.9 | 58.0 | 87.0 |
| 27 ft | 52.7 | 35.0 | 46.1 | 69.1 |
| 29 ft | 45.7 | 30.4 | 37.2 | 55.8 |
| 31 ft | 40.0 | 26.6 | 30.4 | 45.6 |
| 33 ft | 35.3 | 23.5 | 25.2 | 37.8 |
| 35 ft | 31.3 | 20.9 | 21.1 | 31.7 |
| 37 ft | 28.0 | 18.7 | 17.9 | 26.8 |
| 39 ft | 25.2 | 16.8 | 15.3 | 22.9 |
| 41 ft | 22.8 | 15.2 | 13.2 | 19.7 |
| 43 ft | 20.8 | 13.8 | 11.4 | 17.1 |
| 45 ft | 19.0 | 12.6 | 9.95 | 14.9 |
| 47 ft | 17.4 | 11.6 | 8.73 | 13.1 |
| 49 ft | 16.0 | 10.6 | 7.71 | 11.6 |
| 51 ft | 14.8 | 9.82 | 6.83 | 10.3 |
| 53 ft | 13.7 | 9.10 | 6.09 | 9.13 |
| 55 ft | 12.7 | 8.45 | 5.45 | 8.17 |
| 57 ft | 11.8 | 7.86 | 4.89 | 7.34 |
| 59 ft | 11.0 | 7.34 | 4.41 | 6.62 |
| 61 ft | 10.3 | 6.87 | 3.99 | 5.99 |
| 63 ft | 9.67 | 6.44 | 3.63 | 5.44 |
| 65 ft | 9.09 | 6.05 | 3.30 | 4.95 |
| 67 ft | 8.55 | 5.69 | 3.01 | 4.52 |
| 69 ft | 8.07 | 5.37 | 2.76 | 4.14 |
| 71 ft | 7.62 | 5.07 | 2.53 | 3.80 |
| 73 ft | 7.21 | 4.79 | 2.33 | 3.50 |
| 75 ft | 6.83 | 4.54 | 2.15 | 3.22 |
| 77 ft | 6.48 | 4.31 | 1.99 | 2.98 |
| 79 ft | 6.15 | 4.09 | 1.84 | 2.76 |
| 81 ft | 5.85 | 3.89 | 1.71 | 2.56 |
| 83 ft | 5.57 | 3.71 | 1.59 | 2.38 |
| 85 ft | 5.31 | 3.54 | 1.48 | 2.21 |
| 87 ft | 5.07 | 3.38 | 1.38 | 2.06 |
| 89 ft | 4.85 | 3.23 | 1.29 | 1.93 |
| 91 ft | 4.64 | 3.09 | 1.20 | 1.80 |
| 93 ft | 4.44 | 2.95 | 1.13 | 1.69 |
- 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 57 ft span, a W36×302 carries a factored load of 11.8 kips per foot (LRFD) or an allowable load of 7.86 kips per foot (ASD). A live load of 4.89 kips per foot would deflect it span/360, which is 1.90 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.
W36×302 questions
What does W36×302 mean?
W means a wide flange shape. 36 is its nominal depth in inches (the actual depth is 37.3 in) and 302 is its weight in pounds per foot.
How much does a W36×302 weigh?
302 pounds per foot, so a 20 ft W36×302 weighs about 6,040 pounds.
How far can a W36×302 span?
It depends on the load. Braced along its length, it carries 106.4 kips per foot of factored load at 19 ft and 4.44 kips per foot at 93 ft; the load table has the spans in between. Floor beams are often 56 to 75 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W36×302 a compact section?
Yes. Its flanges (bf/2tf = 4.96) and web (h/tw = 33.9) are both compact for bending in 50 ksi steel.