W12x50 is a wide flange steel beam that is 12.2 in deep with an 8.08 in flange and weighs 50 lb/ft (74 kg/m). Its metric designation is W310x74. All values below come from the AISC Shapes Database v16.0.
W12x50 Dimensions
| Property | Symbol | Imperial | Metric |
|---|---|---|---|
| Nominal weight | W | 50 lb/ft | 74 kg/m |
| Cross-sectional area | A | 14.6 in² | 9,420 mm² |
| Depth | d | 12.2 in | 310 mm |
| Flange width | bf | 8.08 in | 205 mm |
| Web thickness | tw | 0.37 in | 9.4 mm |
| Flange thickness | tf | 0.64 in | 16.3 mm |
| Distance to web toe of fillet (design) | kdes | 1.14 in | 29 mm |
| Distance to web toe of fillet (detailing) | kdet | 1.5 in | 38.1 mm |
| Web center line to flange toe of fillet | k1 | 0.9375 in | 23.8 mm |
| Distance between web toes of fillets | T | 9.25 in | 235 mm |
| Workable gage (inner holes) | WGi | 5.5 in | 140 mm |
W12x50 Section Properties
| Property | Symbol | Imperial | Metric |
|---|---|---|---|
| Moment of inertia, x-axis | Ix | 391 in⁴ | 163 ×10⁶ mm⁴ |
| Elastic section modulus, x-axis | Sx | 64.2 in³ | 1,050 ×10³ mm³ |
| Plastic section modulus, x-axis | Zx | 71.9 in³ | 1,180 ×10³ mm³ |
| Radius of gyration, x-axis | rx | 5.18 in | 132 mm |
| Moment of inertia, y-axis | Iy | 56.3 in⁴ | 23.4 ×10⁶ mm⁴ |
| Elastic section modulus, y-axis | Sy | 13.9 in³ | 228 ×10³ mm³ |
| Plastic section modulus, y-axis | Zy | 21.3 in³ | 349 ×10³ mm³ |
| Radius of gyration, y-axis | ry | 1.96 in | 49.8 mm |
| Torsional constant | J | 1.71 in⁴ | 712 ×10³ mm⁴ |
| Warping constant | Cw | 1,880 in⁶ | 505 ×10⁹ mm⁶ |
| Effective radius of gyration | rts | 2.25 in | 57.2 mm |
| Distance between flange centroids | ho | 11.6 in | 295 mm |
| Flange slenderness | bf/2tf | 6.31 | 6.31 |
| Web slenderness | h/tw | 26.8 | 26.8 |
W12x50 Weight Calculator
Enter a length to get the total weight of a W12x50 beam. A 20 ft length weighs 1,000 lb.
Uses the AISC nominal weight: 50 lb/ft (74 kg/m).
Beams Similar to W12x50
| Shape | Weight (lb/ft) | Depth (in) | Flange width (in) |
|---|---|---|---|
| W12x53 | 53 | 12.1 | 10 |
| W12x45 | 45 | 12.1 | 8.05 |
| 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? W12x50 is listed as W310x74 in the metric wide flange beam sizes chart.
W12x50 FAQ
What does W12x50 mean?
W means wide flange. The first number (12) is the nominal depth in inches, and the second number (50) is the weight in pounds per foot. The actual depth of W12x50 is 12.2 in. How to read steel beam sizes.
How much does a W12x50 beam weigh?
W12x50 weighs 50 lb per foot (74 kg per meter). A 20 ft beam weighs about 1,000 lb. Use the calculator above for any length.
What is the metric equivalent of W12x50?
The metric (SI) designation is W310x74: 310 mm deep with a 205 mm flange and 74 kg/m.
How far can a W12x50 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.