W18×119 Steel Beam
A W18×119 is a wide flange steel beam 19 inches deep with 11.3-inch flanges, weighing 119 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 983 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 373 kips.
Design a W18×119 beam Opens a 30 ft span in the free beam designer.
W18×119 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 19.0 in |
| Flange width, bf | 11.3 in |
| Flange thickness, tf | 1.06 in |
| Web thickness, tw | 0.655 in |
| Distance to web toe of fillet, kdes | 1.46 in |
| Distance between flange centroids, ho | 17.94 in |
| Cross-sectional area, A | 35.1 in2 |
| Weight | 119 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W18×119 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 2190 in4 | 253 in4 |
| Elastic section modulus, S | 231 in3 | 44.9 in3 |
| Plastic section modulus, Z | 262 in3 | 69.1 in3 |
| Radius of gyration, r | 7.90 in | 2.69 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 10.6 in4 |
| Warping constant, Cw | 20300 in6 |
| Effective radius of gyration, rts | 3.13 in |
| Flange slenderness, bf/2tf | 5.31 |
| Web slenderness, h/tw | 24.5 |
W18×119 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 = 983 kip-ft | Mn/Ω = 654 kip-ft |
| Shear | φVn = 373 kips | Vn/Ω = 249 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 9.5 ft between braces it keeps its full strength; past Lr = 34.3 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 983 kip-ft | 654 kip-ft |
| 9.5 ft (Lp) | 983 kip-ft | 654 kip-ft |
| 10 ft | 975 kip-ft | 649 kip-ft |
| 20 ft | 823 kip-ft | 548 kip-ft |
| 30 ft | 671 kip-ft | 447 kip-ft |
| 34.3 ft (Lr) | 606 kip-ft | 403 kip-ft |
| 40 ft | 503 kip-ft | 335 kip-ft |
| 50 ft | 390 kip-ft | 259 kip-ft |
| 60 ft | 319 kip-ft | 212 kip-ft |
| 70 ft | 270 kip-ft | 180 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.
W18×119 load table by span
The largest uniform load a simply supported W18×119 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 0.119 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 10 ft | 74.7* | 49.8* | 94.1 | 141.1 |
| 12 ft | 54.6 | 36.3 | 54.4 | 81.7 |
| 14 ft | 40.1 | 26.7 | 34.3 | 51.4 |
| 16 ft | 30.7 | 20.4 | 23.0 | 34.5 |
| 18 ft | 24.3 | 16.1 | 16.1 | 24.2 |
| 20 ft | 19.7 | 13.1 | 11.8 | 17.6 |
| 22 ft | 16.2 | 10.8 | 8.84 | 13.3 |
| 24 ft | 13.6 | 9.08 | 6.81 | 10.2 |
| 26 ft | 11.6 | 7.74 | 5.35 | 8.03 |
| 28 ft | 10.0 | 6.67 | 4.29 | 6.43 |
| 30 ft | 8.73 | 5.81 | 3.48 | 5.23 |
| 32 ft | 7.68 | 5.11 | 2.87 | 4.31 |
| 34 ft | 6.80 | 4.52 | 2.39 | 3.59 |
| 36 ft | 6.06 | 4.04 | 2.02 | 3.02 |
| 38 ft | 5.44 | 3.62 | 1.71 | 2.57 |
| 40 ft | 4.91 | 3.27 | 1.47 | 2.21 |
| 42 ft | 4.46 | 2.96 | 1.27 | 1.90 |
| 44 ft | 4.06 | 2.70 | 1.10 | 1.66 |
| 46 ft | 3.71 | 2.47 | 0.97 | 1.45 |
| 48 ft | 3.41 | 2.27 | 0.85 | 1.28 |
- 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 W18×119 carries a factored load of 8.73 kips per foot (LRFD) or an allowable load of 5.81 kips per foot (ASD). A live load of 3.48 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.
W18×119 questions
What does W18×119 mean?
W means a wide flange shape. 18 is its nominal depth in inches (the actual depth is 19.0 in) and 119 is its weight in pounds per foot.
How much does a W18×119 weigh?
119 pounds per foot, so a 20 ft W18×119 weighs about 2,380 pounds.
How far can a W18×119 span?
It depends on the load. Braced along its length, it carries 74.7 kips per foot of factored load at 10 ft and 3.41 kips per foot at 48 ft; the load table has the spans in between. Floor beams are often 29 to 38 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W18×119 a compact section?
Yes. Its flanges (bf/2tf = 5.31) and web (h/tw = 24.5) are both compact for bending in 50 ksi steel.