W12x72 is a wide flange steel beam that is 12.3 in deep with a 12 in flange and weighs 72 lb/ft (107 kg/m). Its metric designation is W310x107. All values below come from the AISC Shapes Database v16.0.
W12x72 Dimensions
| Property | Symbol | Imperial | Metric |
|---|---|---|---|
| Nominal weight | W | 72 lb/ft | 107 kg/m |
| Cross-sectional area | A | 21.1 in² | 13,600 mm² |
| Depth | d | 12.3 in | 312 mm |
| Flange width | bf | 12 in | 305 mm |
| Web thickness | tw | 0.43 in | 10.9 mm |
| Flange thickness | tf | 0.67 in | 17 mm |
| Distance to web toe of fillet (design) | kdes | 1.27 in | 32.3 mm |
| Distance to web toe of fillet (detailing) | kdet | 1.5625 in | 39.7 mm |
| Web center line to flange toe of fillet | k1 | 1.0625 in | 27 mm |
| Distance between web toes of fillets | T | 9.125 in | 232 mm |
| Workable gage (inner holes) | WGi | 5.5 in | 140 mm |
W12x72 Section Properties
| Property | Symbol | Imperial | Metric |
|---|---|---|---|
| Moment of inertia, x-axis | Ix | 597 in⁴ | 248 ×10⁶ mm⁴ |
| Elastic section modulus, x-axis | Sx | 97.4 in³ | 1,600 ×10³ mm³ |
| Plastic section modulus, x-axis | Zx | 108 in³ | 1,770 ×10³ mm³ |
| Radius of gyration, x-axis | rx | 5.31 in | 135 mm |
| Moment of inertia, y-axis | Iy | 195 in⁴ | 81.2 ×10⁶ mm⁴ |
| Elastic section modulus, y-axis | Sy | 32.4 in³ | 531 ×10³ mm³ |
| Plastic section modulus, y-axis | Zy | 49.2 in³ | 806 ×10³ mm³ |
| Radius of gyration, y-axis | ry | 3.04 in | 77.2 mm |
| Torsional constant | J | 2.93 in⁴ | 1,220 ×10³ mm⁴ |
| Warping constant | Cw | 6,540 in⁶ | 1,760 ×10⁹ mm⁶ |
| Effective radius of gyration | rts | 3.41 in | 86.6 mm |
| Distance between flange centroids | ho | 11.6 in | 295 mm |
| Flange slenderness | bf/2tf | 8.99 | 8.99 |
| Web slenderness | h/tw | 22.6 | 22.6 |
W12x72 Weight Calculator
Enter a length to get the total weight of a W12x72 beam. A 20 ft length weighs 1,440 lb.
Uses the AISC nominal weight: 72 lb/ft (107 kg/m).
Beams Similar to W12x72
| Shape | Weight (lb/ft) | Depth (in) | Flange width (in) |
|---|---|---|---|
| W12x79 | 79 | 12.4 | 12.1 |
| W12x65 | 65 | 12.1 | 12 |
| W12x58 | 58 | 12.2 | 10 |
See every W12 size in the W12 beam sizes chart, or compare all shapes in the wide flange beam sizes chart. Working in millimetres? W12x72 is listed as W310x107 in the metric wide flange beam sizes chart.
W12x72 FAQ
What does W12x72 mean?
W means wide flange. The first number (12) is the nominal depth in inches, and the second number (72) is the weight in pounds per foot. The actual depth of W12x72 is 12.3 in. How to read steel beam sizes.
How much does a W12x72 beam weigh?
W12x72 weighs 72 lb per foot (107 kg per meter). A 20 ft beam weighs about 1,440 lb. Use the calculator above for any length.
What is the metric equivalent of W12x72?
The metric (SI) designation is W310x107: 312 mm deep with a 305 mm flange and 107 kg/m.
How far can a W12x72 beam span?
Span depends on the load, support conditions, deflection limits and local building code, so it cannot be read from a size table. A licensed structural engineer must size any beam that carries a load.
Source: AISC Shapes Database v16.0, consistent with the AISC Steel Construction Manual, 16th Edition. Last updated: September 2026.
This page is reference information only and is not engineering advice. Do not use it for a specific design without verification by a licensed engineer or architect. Full disclaimer.