W18×192 Steel Beam
A W18×192 is a wide flange steel beam 20.4 inches deep with 11.5-inch flanges, weighing 192 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 1,658 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 588 kips.
Design a W18×192 beam Opens a 30 ft span in the free beam designer.
W18×192 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 20.4 in |
| Flange width, bf | 11.5 in |
| Flange thickness, tf | 1.75 in |
| Web thickness, tw | 0.960 in |
| Distance to web toe of fillet, kdes | 2.15 in |
| Distance between flange centroids, ho | 18.65 in |
| Cross-sectional area, A | 56.4 in2 |
| Weight | 192 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W18×192 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 3870 in4 | 440 in4 |
| Elastic section modulus, S | 380 in3 | 76.8 in3 |
| Plastic section modulus, Z | 442 in3 | 119 in3 |
| Radius of gyration, r | 8.28 in | 2.79 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 44.7 in4 |
| Warping constant, Cw | 38000 in6 |
| Effective radius of gyration, rts | 3.28 in |
| Flange slenderness, bf/2tf | 3.27 |
| Web slenderness, h/tw | 16.7 |
W18×192 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 = 1,658 kip-ft | Mn/Ω = 1,103 kip-ft |
| Shear | φVn = 588 kips | Vn/Ω = 392 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 9.9 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 | 1,658 kip-ft | 1,103 kip-ft |
| 9.9 ft (Lp) | 1,658 kip-ft | 1,103 kip-ft |
| 10 ft | 1,655 kip-ft | 1,101 kip-ft |
| 20 ft | 1,495 kip-ft | 995 kip-ft |
| 30 ft | 1,335 kip-ft | 888 kip-ft |
| 40 ft | 1,174 kip-ft | 781 kip-ft |
| 50 ft | 1,014 kip-ft | 675 kip-ft |
| 51.0 ft (Lr) | 997 kip-ft | 663 kip-ft |
| 60 ft | 842 kip-ft | 560 kip-ft |
| 70 ft | 717 kip-ft | 477 kip-ft |
| 80 ft | 626 kip-ft | 416 kip-ft |
| 90 ft | 555 kip-ft | 369 kip-ft |
| 100 ft | 498 kip-ft | 332 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.
W18×192 load table by span
The largest uniform load a simply supported W18×192 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 0.192 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 10 ft | 117.5* | 78.3* | 166.3 | 249.4 |
| 12 ft | 92.1 | 61.3 | 96.2 | 144.3 |
| 14 ft | 67.7 | 45.0 | 60.6 | 90.9 |
| 16 ft | 51.8 | 34.5 | 40.6 | 60.9 |
| 18 ft | 40.9 | 27.2 | 28.5 | 42.8 |
| 20 ft | 33.2 | 22.1 | 20.8 | 31.2 |
| 22 ft | 27.4 | 18.2 | 15.6 | 23.4 |
| 24 ft | 23.0 | 15.3 | 12.0 | 18.0 |
| 26 ft | 19.6 | 13.1 | 9.46 | 14.2 |
| 28 ft | 16.9 | 11.3 | 7.57 | 11.4 |
| 30 ft | 14.7 | 9.80 | 6.16 | 9.24 |
| 32 ft | 12.9 | 8.62 | 5.07 | 7.61 |
| 34 ft | 11.5 | 7.63 | 4.23 | 6.35 |
| 36 ft | 10.2 | 6.81 | 3.56 | 5.35 |
| 38 ft | 9.18 | 6.11 | 3.03 | 4.55 |
| 40 ft | 8.29 | 5.51 | 2.60 | 3.90 |
| 42 ft | 7.52 | 5.00 | 2.24 | 3.37 |
| 44 ft | 6.85 | 4.56 | 1.95 | 2.93 |
| 46 ft | 6.27 | 4.17 | 1.71 | 2.56 |
| 48 ft | 5.76 | 3.83 | 1.50 | 2.26 |
| 50 ft | 5.30 | 3.53 | 1.33 | 2.00 |
- 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 30 ft span, a W18×192 carries a factored load of 14.7 kips per foot (LRFD) or an allowable load of 9.80 kips per foot (ASD). A live load of 6.16 kips per foot would deflect it span/360, which is 1.00 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.
W18×192 questions
What does W18×192 mean?
W means a wide flange shape. 18 is its nominal depth in inches (the actual depth is 20.4 in) and 192 is its weight in pounds per foot.
How much does a W18×192 weigh?
192 pounds per foot, so a 20 ft W18×192 weighs about 3,840 pounds.
How far can a W18×192 span?
It depends on the load. Braced along its length, it carries 117.5 kips per foot of factored load at 10 ft and 5.30 kips per foot at 50 ft; the load table has the spans in between. Floor beams are often 31 to 41 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W18×192 a compact section?
Yes. Its flanges (bf/2tf = 3.27) and web (h/tw = 16.7) are both compact for bending in 50 ksi steel.