W36×232 Steel Beam
A W36×232 is a wide flange steel beam 37.1 inches deep with 12.1-inch flanges, weighing 232 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 3,510 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 968 kips.
Design a W36×232 beam Opens a 57 ft span in the free beam designer.
W36×232 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 37.1 in |
| Flange width, bf | 12.1 in |
| Flange thickness, tf | 1.57 in |
| Web thickness, tw | 0.870 in |
| Distance to web toe of fillet, kdes | 2.32 in |
| Distance between flange centroids, ho | 35.53 in |
| Cross-sectional area, A | 68.1 in2 |
| Weight | 232 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W36×232 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 15000 in4 | 468 in4 |
| Elastic section modulus, S | 809 in3 | 77.2 in3 |
| Plastic section modulus, Z | 936 in3 | 122 in3 |
| Radius of gyration, r | 14.8 in | 2.62 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 39.6 in4 |
| Warping constant, Cw | 148000 in6 |
| Effective radius of gyration, rts | 3.21 in |
| Flange slenderness, bf/2tf | 3.86 |
| Web slenderness, h/tw | 37.3 |
W36×232 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 = 3,510 kip-ft | Mn/Ω = 2,335 kip-ft |
| Shear | φVn = 968 kips | Vn/Ω = 646 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 9.3 ft between braces it keeps its full strength; past Lr = 29.9 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 3,510 kip-ft | 2,335 kip-ft |
| 5 ft | 3,510 kip-ft | 2,335 kip-ft |
| 9.3 ft (Lp) | 3,510 kip-ft | 2,335 kip-ft |
| 10 ft | 3,460 kip-ft | 2,302 kip-ft |
| 15 ft | 3,125 kip-ft | 2,079 kip-ft |
| 20 ft | 2,790 kip-ft | 1,856 kip-ft |
| 25 ft | 2,454 kip-ft | 1,633 kip-ft |
| 29.9 ft (Lr) | 2,124 kip-ft | 1,413 kip-ft |
| 30 ft (Lr) | 2,115 kip-ft | 1,407 kip-ft |
| 35 ft | 1,708 kip-ft | 1,136 kip-ft |
| 40 ft | 1,431 kip-ft | 952 kip-ft |
| 45 ft | 1,232 kip-ft | 820 kip-ft |
| 50 ft | 1,083 kip-ft | 720 kip-ft |
| 55 ft | 966 kip-ft | 643 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.
W36×232 load table by span
The largest uniform load a simply supported W36×232 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 0.232 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 19 ft | 77.8 | 51.8 | 94.0 | 140.9 |
| 21 ft | 63.7 | 42.4 | 69.6 | 104.4 |
| 23 ft | 53.1 | 35.3 | 53.0 | 79.4 |
| 25 ft | 44.9 | 29.9 | 41.2 | 61.9 |
| 27 ft | 38.5 | 25.6 | 32.7 | 49.1 |
| 29 ft | 33.4 | 22.2 | 26.4 | 39.6 |
| 31 ft | 29.2 | 19.4 | 21.6 | 32.4 |
| 33 ft | 25.8 | 17.2 | 17.9 | 26.9 |
| 35 ft | 22.9 | 15.3 | 15.0 | 22.5 |
| 37 ft | 20.5 | 13.6 | 12.7 | 19.1 |
| 39 ft | 18.5 | 12.3 | 10.9 | 16.3 |
| 41 ft | 16.7 | 11.1 | 9.35 | 14.0 |
| 43 ft | 15.2 | 10.1 | 8.11 | 12.2 |
| 45 ft | 13.9 | 9.23 | 7.07 | 10.6 |
| 47 ft | 12.7 | 8.46 | 6.21 | 9.31 |
| 49 ft | 11.7 | 7.78 | 5.48 | 8.22 |
| 51 ft | 10.8 | 7.18 | 4.86 | 7.29 |
| 53 ft | 10.00 | 6.65 | 4.33 | 6.49 |
| 55 ft | 9.28 | 6.18 | 3.87 | 5.81 |
| 57 ft | 8.64 | 5.75 | 3.48 | 5.22 |
| 59 ft | 8.07 | 5.37 | 3.14 | 4.71 |
| 61 ft | 7.55 | 5.02 | 2.84 | 4.26 |
| 63 ft | 7.07 | 4.71 | 2.58 | 3.87 |
| 65 ft | 6.65 | 4.42 | 2.35 | 3.52 |
| 67 ft | 6.26 | 4.16 | 2.14 | 3.21 |
| 69 ft | 5.90 | 3.92 | 1.96 | 2.94 |
| 71 ft | 5.57 | 3.71 | 1.80 | 2.70 |
| 73 ft | 5.27 | 3.51 | 1.66 | 2.48 |
| 75 ft | 4.99 | 3.32 | 1.53 | 2.29 |
| 77 ft | 4.74 | 3.15 | 1.41 | 2.12 |
| 79 ft | 4.50 | 2.99 | 1.31 | 1.96 |
| 81 ft | 4.28 | 2.85 | 1.21 | 1.82 |
| 83 ft | 4.08 | 2.71 | 1.13 | 1.69 |
| 85 ft | 3.89 | 2.59 | 1.05 | 1.57 |
| 87 ft | 3.71 | 2.47 | 0.98 | 1.47 |
| 89 ft | 3.55 | 2.36 | 0.91 | 1.37 |
| 91 ft | 3.39 | 2.26 | 0.86 | 1.28 |
| 93 ft | 3.25 | 2.16 | 0.80 | 1.20 |
- 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 W36×232 carries a factored load of 8.64 kips per foot (LRFD) or an allowable load of 5.75 kips per foot (ASD). A live load of 3.48 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.
W36×232 questions
What does W36×232 mean?
W means a wide flange shape. 36 is its nominal depth in inches (the actual depth is 37.1 in) and 232 is its weight in pounds per foot.
How much does a W36×232 weigh?
232 pounds per foot, so a 20 ft W36×232 weighs about 4,640 pounds.
How far can a W36×232 span?
It depends on the load. Braced along its length, it carries 77.8 kips per foot of factored load at 19 ft and 3.25 kips per foot at 93 ft; the load table has the spans in between. Floor beams are often 56 to 74 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W36×232 a compact section?
Yes. Its flanges (bf/2tf = 3.86) and web (h/tw = 37.3) are both compact for bending in 50 ksi steel.