W27×217 Steel Beam
A W27×217 is a wide flange steel beam 28.4 inches deep with 14.1-inch flanges, weighing 217 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 2,666 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 707 kips.
Design a W27×217 beam Opens a 42 ft span in the free beam designer.
W27×217 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 28.4 in |
| Flange width, bf | 14.1 in |
| Flange thickness, tf | 1.50 in |
| Web thickness, tw | 0.830 in |
| Distance to web toe of fillet, kdes | 2.29 in |
| Distance between flange centroids, ho | 26.90 in |
| Cross-sectional area, A | 64.0 in2 |
| Weight | 217 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W27×217 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 8910 in4 | 704 in4 |
| Elastic section modulus, S | 627 in3 | 100 in3 |
| Plastic section modulus, Z | 711 in3 | 154 in3 |
| Radius of gyration, r | 11.8 in | 3.32 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 37.6 in4 |
| Warping constant, Cw | 128000 in6 |
| Effective radius of gyration, rts | 3.89 in |
| Flange slenderness, bf/2tf | 4.71 |
| Web slenderness, h/tw | 28.7 |
W27×217 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 = 2,666 kip-ft | Mn/Ω = 1,774 kip-ft |
| Shear | φVn = 707 kips | Vn/Ω = 471 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 = 40.8 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 2,666 kip-ft | 1,774 kip-ft |
| 10 ft | 2,666 kip-ft | 1,774 kip-ft |
| 11.7 ft (Lp) | 2,666 kip-ft | 1,774 kip-ft |
| 20 ft | 2,376 kip-ft | 1,581 kip-ft |
| 30 ft | 2,026 kip-ft | 1,348 kip-ft |
| 40 ft | 1,676 kip-ft | 1,115 kip-ft |
| 40.9 ft (Lr) | 1,644 kip-ft | 1,094 kip-ft |
| 50 ft | 1,283 kip-ft | 853 kip-ft |
| 60 ft | 1,037 kip-ft | 690 kip-ft |
| 70 ft | 871 kip-ft | 580 kip-ft |
| 80 ft | 753 kip-ft | 501 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.
W27×217 load table by span
The largest uniform load a simply supported W27×217 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 0.217 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 14 ft | 101.0* | 67.3* | 139.5 | 209.3 |
| 16 ft | 83.3 | 55.4 | 93.5 | 140.2 |
| 18 ft | 65.8 | 43.8 | 65.6 | 98.5 |
| 20 ft | 53.3 | 35.5 | 47.8 | 71.8 |
| 22 ft | 44.1 | 29.3 | 36.0 | 53.9 |
| 24 ft | 37.0 | 24.6 | 27.7 | 41.5 |
| 26 ft | 31.6 | 21.0 | 21.8 | 32.7 |
| 28 ft | 27.2 | 18.1 | 17.4 | 26.2 |
| 30 ft | 23.7 | 15.8 | 14.2 | 21.3 |
| 32 ft | 20.8 | 13.9 | 11.7 | 17.5 |
| 34 ft | 18.5 | 12.3 | 9.74 | 14.6 |
| 36 ft | 16.5 | 11.0 | 8.20 | 12.3 |
| 38 ft | 14.8 | 9.83 | 6.98 | 10.5 |
| 40 ft | 13.3 | 8.87 | 5.98 | 8.97 |
| 42 ft | 12.1 | 8.05 | 5.17 | 7.75 |
| 44 ft | 11.0 | 7.33 | 4.49 | 6.74 |
| 46 ft | 10.1 | 6.71 | 3.93 | 5.90 |
| 48 ft | 9.26 | 6.16 | 3.46 | 5.19 |
| 50 ft | 8.53 | 5.68 | 3.06 | 4.59 |
| 52 ft | 7.89 | 5.25 | 2.72 | 4.08 |
| 54 ft | 7.31 | 4.87 | 2.43 | 3.65 |
| 56 ft | 6.80 | 4.53 | 2.18 | 3.27 |
| 58 ft | 6.34 | 4.22 | 1.96 | 2.94 |
| 60 ft | 5.93 | 3.94 | 1.77 | 2.66 |
| 62 ft | 5.55 | 3.69 | 1.61 | 2.41 |
| 64 ft | 5.21 | 3.46 | 1.46 | 2.19 |
| 66 ft | 4.90 | 3.26 | 1.33 | 2.00 |
| 68 ft | 4.61 | 3.07 | 1.22 | 1.83 |
| 70 ft | 4.35 | 2.90 | 1.12 | 1.67 |
- 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 42 ft span, a W27×217 carries a factored load of 12.1 kips per foot (LRFD) or an allowable load of 8.05 kips per foot (ASD). A live load of 5.17 kips per foot would deflect it span/360, which is 1.40 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.
W27×217 questions
What does W27×217 mean?
W means a wide flange shape. 27 is its nominal depth in inches (the actual depth is 28.4 in) and 217 is its weight in pounds per foot.
How much does a W27×217 weigh?
217 pounds per foot, so a 20 ft W27×217 weighs about 4,340 pounds.
How far can a W27×217 span?
It depends on the load. Braced along its length, it carries 101.0 kips per foot of factored load at 14 ft and 4.35 kips per foot at 70 ft; the load table has the spans in between. Floor beams are often 43 to 57 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W27×217 a compact section?
Yes. Its flanges (bf/2tf = 4.71) and web (h/tw = 28.7) are both compact for bending in 50 ksi steel.