W14×665 Steel Beam
A W14×665 is a wide flange steel beam 21.6 inches deep with 17.7-inch flanges, weighing 665 pounds per foot. In ASTM A992 steel (Fy = 50 ksi) it has a design bending strength of 5,550 kip-ft (LRFD) when its compression flange is braced, and a design shear strength of 1,834 kips.
Design a W14×665 beam Opens a 33 ft span in the free beam designer.
W14×665 dimensions
| Dimension | Value |
|---|---|
| Depth, d | 21.6 in |
| Flange width, bf | 17.7 in |
| Flange thickness, tf | 4.52 in |
| Web thickness, tw | 2.83 in |
| Distance to web toe of fillet, kdes | 5.12 in |
| Distance between flange centroids, ho | 17.08 in |
| Cross-sectional area, A | 196 in2 |
| Weight | 665 lb/ft |
Dimensions are AISC design values. Detailing dimensions are rounded to the nearest 1/16 in.
W14×665 section properties
| Property | Strong axis (x) | Weak axis (y) |
|---|---|---|
| Moment of inertia, I | 12400 in4 | 4170 in4 |
| Elastic section modulus, S | 1150 in3 | 472 in3 |
| Plastic section modulus, Z | 1480 in3 | 730 in3 |
| Radius of gyration, r | 7.98 in | 4.62 in |
| Torsion and slenderness | Value |
|---|---|
| Torsional constant, J | 1120 in4 |
| Warping constant, Cw | 305000 in6 |
| Effective radius of gyration, rts | 5.57 in |
| Flange slenderness, bf/2tf | 1.95 |
| Web slenderness, h/tw | 4.03 |
W14×665 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 = 5,550 kip-ft | Mn/Ω = 3,693 kip-ft |
| Shear | φVn = 1,834 kips | Vn/Ω = 1,223 kips |
If the compression flange isn't braced, the beam can buckle sideways before it yields. Up to Lp = 16.3 ft between braces it keeps its full strength; past Lr = 253.3 ft it buckles elastically. With uniform moment between braces (Cb = 1.0):
| Unbraced length, Lb | φMn (LRFD) | Mn/Ω (ASD) |
|---|---|---|
| Braced | 5,550 kip-ft | 3,693 kip-ft |
| 10 ft | 5,550 kip-ft | 3,693 kip-ft |
| 16.3 ft (Lp) | 5,550 kip-ft | 3,693 kip-ft |
| 20 ft | 5,511 kip-ft | 3,666 kip-ft |
| 30 ft | 5,404 kip-ft | 3,595 kip-ft |
| 40 ft | 5,297 kip-ft | 3,524 kip-ft |
| 50 ft | 5,190 kip-ft | 3,453 kip-ft |
| 60 ft | 5,083 kip-ft | 3,382 kip-ft |
| 70 ft | 4,977 kip-ft | 3,311 kip-ft |
| 80 ft | 4,870 kip-ft | 3,240 kip-ft |
| 90 ft | 4,763 kip-ft | 3,169 kip-ft |
| 100 ft | 4,656 kip-ft | 3,098 kip-ft |
| 110 ft | 4,549 kip-ft | 3,027 kip-ft |
| 253.3 ft (Lr) | 3,019 kip-ft | 2,008 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.
W14×665 load table by span
The largest uniform load a simply supported W14×665 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 0.665 kips per foot.
| Span | Factored load (LRFD) | Allowable load (ASD) | Load at span/360 | Load at span/240 |
|---|---|---|---|---|
| 11 ft | 333.4* | 222.3* | 400.3 | 600.4 |
| 13 ft | 262.7 | 174.8 | 242.5 | 363.7 |
| 15 ft | 197.3 | 131.3 | 157.8 | 236.8 |
| 17 ft | 153.6 | 102.2 | 108.4 | 162.7 |
| 19 ft | 123.0 | 81.8 | 77.7 | 116.5 |
| 21 ft | 100.7 | 67.0 | 57.5 | 86.3 |
| 23 ft | 83.9 | 55.8 | 43.8 | 65.7 |
| 25 ft | 71.0 | 47.3 | 34.1 | 51.1 |
| 27 ft | 60.9 | 40.5 | 27.1 | 40.6 |
| 29 ft | 52.8 | 35.1 | 21.8 | 32.8 |
| 31 ft | 46.2 | 30.7 | 17.9 | 26.8 |
| 33 ft | 40.8 | 27.1 | 14.8 | 22.2 |
| 35 ft | 36.2 | 24.1 | 12.4 | 18.6 |
| 37 ft | 32.4 | 21.6 | 10.5 | 15.8 |
| 39 ft | 29.2 | 19.4 | 8.98 | 13.5 |
| 41 ft | 26.4 | 17.6 | 7.73 | 11.6 |
| 43 ft | 24.0 | 16.0 | 6.70 | 10.1 |
| 45 ft | 21.9 | 14.6 | 5.85 | 8.77 |
| 47 ft | 20.1 | 13.4 | 5.13 | 7.70 |
| 49 ft | 18.5 | 12.3 | 4.53 | 6.79 |
| 51 ft | 17.1 | 11.4 | 4.02 | 6.02 |
| 53 ft | 15.8 | 10.5 | 3.58 | 5.37 |
- 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 33 ft span, a W14×665 carries a factored load of 40.8 kips per foot (LRFD) or an allowable load of 27.1 kips per foot (ASD). A live load of 14.8 kips per foot would deflect it span/360, which is 1.10 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.
W14×665 questions
What does W14×665 mean?
W means a wide flange shape. 14 is its nominal depth in inches (the actual depth is 21.6 in) and 665 is its weight in pounds per foot.
How much does a W14×665 weigh?
665 pounds per foot, so a 20 ft W14×665 weighs about 13,300 pounds.
How far can a W14×665 span?
It depends on the load. Braced along its length, it carries 333.4 kips per foot of factored load at 11 ft and 15.8 kips per foot at 53 ft; the load table has the spans in between. Floor beams are often 32 to 43 ft for this depth (span-to-depth ratios of about 18 to 24), where deflection usually governs.
Is a W14×665 a compact section?
Yes. Its flanges (bf/2tf = 1.95) and web (h/tw = 4.03) are both compact for bending in 50 ksi steel.