W36×395 Steel Beam
A W36×395 is a wide flange steel beam 38.4 inches deep with 16.8-inch flanges, weighing 395 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 6,413 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,405 kips.
Design a W36×395 beam Opens a 57 ft span in the free beam designer.
W36×395 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 38.4 in |
| Flange width, bf | 16.8 in |
| Flange thickness, tf | 2.20 in |
| Web thickness, tw | 1.22 in |
| Distance to web toe of fillet, kdes | 3.15 in |
| Distance between flange centroids, ho | 36.20 in |
| Cross-sectional area, A | 116 in2 |
| Weight | 395 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W36×395 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 28500 in4 | 1750 in4 |
| Elastic section modulus, S | 1490 in3 | 208 in3 |
| Plastic section modulus, Z | 1710 in3 | 325 in3 |
| Radius of gyration, r | 15.7 in | 3.88 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 142 in4 |
| Warping constant, Cw | 575000 in6 |
| Effective radius of gyration, rts | 4.61 in |
| Flange slenderness, bf/2tf | 3.83 |
| Web slenderness, h/tw | 26.3 |
W36×395 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 = 6,413 kip-ft | Mn/Ω = 4,266 kip-ft |
| Shear | φVn = 1,405 kips | Vn/Ω = 937 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 13.7 ft between braces it keeps its full strength; past Lr = 51.0 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 6,413 kip-ft | 4,266 kip-ft |
| 10 ft | 6,413 kip-ft | 4,266 kip-ft |
| 13.7 ft (Lp) | 6,413 kip-ft | 4,266 kip-ft |
| 20 ft | 5,990 kip-ft | 3,985 kip-ft |
| 30 ft | 5,318 kip-ft | 3,539 kip-ft |
| 40 ft | 4,647 kip-ft | 3,092 kip-ft |
| 50 ft | 3,976 kip-ft | 2,645 kip-ft |
| 51.0 ft (Lr) | 3,911 kip-ft | 2,602 kip-ft |
| 60 ft | 3,218 kip-ft | 2,141 kip-ft |
| 70 ft | 2,696 kip-ft | 1,794 kip-ft |
| 80 ft | 2,324 kip-ft | 1,546 kip-ft |
| 90 ft | 2,043 kip-ft | 1,360 kip-ft |
| 100 ft | 1,825 kip-ft | 1,214 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.
W36×395 load table by span
The largest uniform load a simply supported W36×395 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 0.395 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 19 ft | 142.1 | 94.5 | 178.5 | 267.8 |
| 21 ft | 116.3 | 77.4 | 132.2 | 198.3 |
| 23 ft | 97.0 | 64.5 | 100.6 | 151.0 |
| 25 ft | 82.1 | 54.6 | 78.4 | 117.5 |
| 27 ft | 70.4 | 46.8 | 62.2 | 93.3 |
| 29 ft | 61.0 | 40.6 | 50.2 | 75.3 |
| 31 ft | 53.4 | 35.5 | 41.1 | 61.7 |
| 33 ft | 47.1 | 31.3 | 34.1 | 51.1 |
| 35 ft | 41.9 | 27.9 | 28.6 | 42.8 |
| 37 ft | 37.5 | 24.9 | 24.2 | 36.3 |
| 39 ft | 33.7 | 22.4 | 20.6 | 31.0 |
| 41 ft | 30.5 | 20.3 | 17.8 | 26.6 |
| 43 ft | 27.7 | 18.5 | 15.4 | 23.1 |
| 45 ft | 25.3 | 16.9 | 13.4 | 20.2 |
| 47 ft | 23.2 | 15.5 | 11.8 | 17.7 |
| 49 ft | 21.4 | 14.2 | 10.4 | 15.6 |
| 51 ft | 19.7 | 13.1 | 9.23 | 13.8 |
| 53 ft | 18.3 | 12.2 | 8.22 | 12.3 |
| 55 ft | 17.0 | 11.3 | 7.36 | 11.0 |
| 57 ft | 15.8 | 10.5 | 6.61 | 9.92 |
| 59 ft | 14.7 | 9.81 | 5.96 | 8.94 |
| 61 ft | 13.8 | 9.17 | 5.39 | 8.09 |
| 63 ft | 12.9 | 8.60 | 4.90 | 7.35 |
| 65 ft | 12.1 | 8.08 | 4.46 | 6.69 |
| 67 ft | 11.4 | 7.60 | 4.07 | 6.11 |
| 69 ft | 10.8 | 7.17 | 3.73 | 5.59 |
| 71 ft | 10.2 | 6.77 | 3.42 | 5.13 |
| 73 ft | 9.63 | 6.40 | 3.15 | 4.72 |
| 75 ft | 9.12 | 6.07 | 2.90 | 4.35 |
| 77 ft | 8.65 | 5.76 | 2.68 | 4.02 |
| 79 ft | 8.22 | 5.47 | 2.48 | 3.73 |
| 81 ft | 7.82 | 5.20 | 2.30 | 3.46 |
| 83 ft | 7.45 | 4.95 | 2.14 | 3.21 |
| 85 ft | 7.10 | 4.72 | 1.99 | 2.99 |
| 87 ft | 6.78 | 4.51 | 1.86 | 2.79 |
| 89 ft | 6.48 | 4.31 | 1.74 | 2.61 |
| 91 ft | 6.19 | 4.12 | 1.62 | 2.44 |
| 93 ft | 5.93 | 3.95 | 1.52 | 2.28 |
| 95 ft | 5.68 | 3.78 | 1.43 | 2.14 |
- 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 W36×395 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 6.61 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.
W36×395 questions
What does W36×395 mean?
W means a wide flange shape. 36 is its nominal depth in inches (the actual depth is 38.4 in) and 395 is its weight in pounds per foot.
How much does a W36×395 weigh?
395 pounds per foot, so a 20 ft W36×395 weighs about 7,900 pounds.
How far can a W36×395 span?
It depends on the load. Braced along its length, it carries 142.1 kips per foot of factored load at 19 ft and 5.68 kips per foot at 95 ft; the load table has the spans in between. Floor beams are often 58 to 77 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W36×395 a compact section?
Yes. Its flanges (bf/2tf = 3.83) and web (h/tw = 26.3) are both compact for bending in 50 ksi steel.