W12×230 Steel Beam
A W12×230 is a wide flange steel beam 15.1 inches deep with 12.9-inch flanges, weighing 230 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 1,448 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 584 kips.
Design a W12×230 beam Opens a 24 ft span in the free beam designer.
W12×230 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 15.1 in |
| Flange width, bf | 12.9 in |
| Flange thickness, tf | 2.07 in |
| Web thickness, tw | 1.29 in |
| Distance to web toe of fillet, kdes | 2.67 in |
| Distance between flange centroids, ho | 13.03 in |
| Cross-sectional area, A | 67.7 in2 |
| Weight | 230 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W12×230 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 2420 in4 | 742 in4 |
| Elastic section modulus, S | 321 in3 | 115 in3 |
| Plastic section modulus, Z | 386 in3 | 177 in3 |
| Radius of gyration, r | 5.97 in | 3.31 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 83.8 in4 |
| Warping constant, Cw | 31200 in6 |
| Effective radius of gyration, rts | 3.87 in |
| Flange slenderness, bf/2tf | 3.11 |
| Web slenderness, h/tw | 7.56 |
W12×230 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 = 1,448 kip-ft | Mn/Ω = 963 kip-ft |
| Shear | φVn = 584 kips | Vn/Ω = 390 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 11.7 ft between braces it keeps its full strength; past Lr = 104.7 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 1,448 kip-ft | 963 kip-ft |
| 10 ft | 1,448 kip-ft | 963 kip-ft |
| 11.7 ft (Lp) | 1,448 kip-ft | 963 kip-ft |
| 20 ft | 1,393 kip-ft | 927 kip-ft |
| 30 ft | 1,328 kip-ft | 884 kip-ft |
| 40 ft | 1,263 kip-ft | 841 kip-ft |
| 50 ft | 1,198 kip-ft | 797 kip-ft |
| 60 ft | 1,133 kip-ft | 754 kip-ft |
| 70 ft | 1,068 kip-ft | 711 kip-ft |
| 80 ft | 1,003 kip-ft | 667 kip-ft |
| 90 ft | 938 kip-ft | 624 kip-ft |
| 100 ft | 873 kip-ft | 581 kip-ft |
| 104.7 ft (Lr) | 842 kip-ft | 560 kip-ft |
| 110 ft | 801 kip-ft | 533 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.
W12×230 load table by span
The largest uniform load a simply supported W12×230 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 0.230 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 8 ft | 146.1* | 97.4* | 203.1 | 304.6 |
| 10 ft | 115.8 | 77.0 | 104.0 | 156.0 |
| 12 ft | 80.4 | 53.5 | 60.2 | 90.3 |
| 14 ft | 59.1 | 39.3 | 37.9 | 56.8 |
| 16 ft | 45.2 | 30.1 | 25.4 | 38.1 |
| 18 ft | 35.7 | 23.8 | 17.8 | 26.7 |
| 20 ft | 29.0 | 19.3 | 13.0 | 19.5 |
| 22 ft | 23.9 | 15.9 | 9.76 | 14.6 |
| 24 ft | 20.1 | 13.4 | 7.52 | 11.3 |
| 26 ft | 17.1 | 11.4 | 5.92 | 8.87 |
| 28 ft | 14.8 | 9.83 | 4.74 | 7.10 |
| 30 ft | 12.9 | 8.56 | 3.85 | 5.78 |
| 32 ft | 11.3 | 7.52 | 3.17 | 4.76 |
| 34 ft | 10.0 | 6.66 | 2.65 | 3.97 |
| 36 ft | 8.94 | 5.94 | 2.23 | 3.34 |
| 38 ft | 8.02 | 5.34 | 1.89 | 2.84 |
- 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 24 ft span, a W12×230 carries a factored load of 20.1 kips per foot (LRFD) or an allowable load of 13.4 kips per foot (ASD). A live load of 7.52 kips per foot would deflect it span/360, which is 0.80 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.
W12×230 questions
What does W12×230 mean?
W means a wide flange shape. 12 is its nominal depth in inches (the actual depth is 15.1 in) and 230 is its weight in pounds per foot.
How much does a W12×230 weigh?
230 pounds per foot, so a 20 ft W12×230 weighs about 4,600 pounds.
How far can a W12×230 span?
It depends on the load. Braced along its length, it carries 146.1 kips per foot of factored load at 8 ft and 8.02 kips per foot at 38 ft; the load table has the spans in between. Floor beams are often 23 to 30 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W12×230 a compact section?
Yes. Its flanges (bf/2tf = 3.11) and web (h/tw = 7.56) are both compact for bending in 50 ksi steel.