W12x26 Section Properties
The W12x26 is a wide-flange steel section weighing 26 lb/ft (38.7 kg/m) with a nominal depth of 12 inches. It is one of the most commonly specified light beam sections in North American steel construction, widely used for residential and light commercial floor framing, roof beams, and secondary structural members.
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Complete Section Properties (Imperial)
| Property | Symbol | Value | Unit |
|---|---|---|---|
| Depth | d | 12.2 | in |
| Flange Width | bf | 6.490 | in |
| Flange Thickness | tf | 0.380 | in |
| Web Thickness | tw | 0.230 | in |
| Cross-Sectional Area | A | 7.65 | in² |
| Weight per Foot | wt | 26 | lb/ft |
| Moment of Inertia (strong axis) | Ix | 204 | in⁴ |
| Elastic Section Modulus (strong axis) | Sx | 33.4 | in³ |
| Plastic Section Modulus (strong axis) | Zx | 37.2 | in³ |
| Radius of Gyration (strong axis) | rx | 5.17 | in |
| Moment of Inertia (weak axis) | Iy | 17.3 | in⁴ |
| Elastic Section Modulus (weak axis) | Sy | 5.34 | in³ |
| Plastic Section Modulus (weak axis) | Zy | 8.17 | in³ |
| Radius of Gyration (weak axis) | ry | 1.51 | in |
| Torsional Constant | J | 0.300 | in⁴ |
| Warping Constant | Cw | 607 | in⁶ |
Metric Equivalents
| Property | Symbol | Value | Unit |
|---|---|---|---|
| Depth | d | 310 | mm |
| Flange Width | bf | 165 | mm |
| Flange Thickness | tf | 9.65 | mm |
| Web Thickness | tw | 5.84 | mm |
| Cross-Sectional Area | A | 4,935 | mm² |
| Weight per Metre | wt | 38.7 | kg/m |
| Moment of Inertia (strong axis) | Ix | 84.9 x 10⁶ | mm⁴ |
| Elastic Section Modulus (strong axis) | Sx | 547 x 10³ | mm³ |
| Plastic Section Modulus (strong axis) | Zx | 610 x 10³ | mm³ |
AISC 360 Compactness Classification
For A992 steel (Fy = 50 ksi, E = 29,000 ksi):
Flange: bf/(2tf) = 6.490 / (2 x 0.380) = 8.54. Compact limit = 0.38 x sqrt(E/Fy) = 0.38 x sqrt(29,000/50) = 9.15. Since 8.54 < 9.15, the flange is compact.
Web: h/tw = (d - 2k) / tw. For W12x26 with k = 0.855 in: h/tw = (12.2 - 2 x 0.855) / 0.230 = 10.49 / 0.230 = 45.6. Compact limit = 3.76 x sqrt(E/Fy) = 3.76 x sqrt(29,000/50) = 90.6. Since 45.6 < 90.6, the web is compact.
Classification: Compact section -- full plastic moment Mp = Fy x Zx can be developed with adequate lateral bracing.
Design Capacity Summary (AISC 360 LRFD, A992 Fy = 50 ksi)
Flexural Capacity (phi = 0.90)
| Unbraced Length Lb | phi x Mn | Governing Limit State |
|---|---|---|
| 0 ft (full bracing) | 139 ft-kips | Yielding (Mp = Fy x Zx) |
| 6 ft | 139 ft-kips | Yielding (Lb < Lp) |
| 10 ft | 119 ft-kips | Inelastic LTB |
| 15 ft | 89.5 ft-kips | Inelastic LTB |
| 20 ft | 60.0 ft-kips | Elastic LTB |
Lateral bracing limits: Lp = 4.67 ft (based on ry = 1.51 in). Lr = 14.0 ft. For unbraced lengths less than Lp, the full plastic moment is available. Between Lp and Lr, moment capacity decreases linearly. Beyond Lr, elastic lateral-torsional buckling governs.
Shear Capacity (phi = 1.00 for compact webs)
phi x Vn = 1.00 x 0.6 x Fy x Aw = 1.00 x 0.6 x 50 x (12.2 x 0.230) = 84.2 kips
Deflection Screening
For a simply supported W12x26 under uniform load (Ix = 204 in⁴):
| Span | Max Service Load for L/360 | Max Service Load for L/240 |
|---|---|---|
| 15 ft | 1.90 kip/ft | 2.84 kip/ft |
| 20 ft | 0.80 kip/ft | 1.20 kip/ft |
| 25 ft | 0.39 kip/ft | 0.59 kip/ft |
Common Applications for W12x26
The W12x26 is a versatile section that strikes a balance between depth efficiency, weight, and bending capacity. Its most common applications include:
- Residential floor beams spanning 15-25 ft with typical live loads of 40 psf. At 20 ft span with 40 psf live load on 8 ft tributary width, the live load deflection is approximately L/400 -- well within the L/360 limit.
- Light commercial roof beams in office buildings, retail spaces, and warehouses with moderate snow or rain loads.
- Mezzanine framing in industrial and warehouse buildings where floor depth is constrained.
- Header beams over garage door openings and wide window spans in steel-framed buildings.
- Composite floor beams with metal deck and concrete slab, where the composite action approximately doubles the effective Ix.
The W12x26 competes directly with the W10x30 (Ix = 170 in⁴, Zx = 36.6 in³) and W14x22 (Ix = 199 in⁴, Zx = 33.2 in³). The W12x26 provides more Ix than either at a weight between the two, making it the preferred choice when deflection controls. When moment capacity is the primary concern and depth is not limited, the W14x22 saves 4 lb/ft at nearly the same Zx.
Available Steel Grades
| Grade | Specification | Fy (ksi) | Fu (ksi) | Status |
|---|---|---|---|---|
| A992 | ASTM A992/A992M | 50 | 65 | Current standard for W-shapes |
| A572 Gr 50 | ASTM A572/A572M | 50 | 65 | Acceptable alternate; less common |
| A36 | ASTM A36/A36M | 36 | 58 | Legacy; rarely produced as W-shapes |
Note: A992 is the default material for all W-shapes in current US practice. Dual-certified A992/A572 Gr 50 material is common. A992 includes a maximum Fy/Fu ratio of 0.85 for ductility in seismic applications.
Comparison with Adjacent Sections
| Property | W10x30 | W12x26 | W14x22 | W12x30 |
|---|---|---|---|---|
| Weight (lb/ft) | 30 | 26 | 22 | 30 |
| d (in) | 10.5 | 12.2 | 13.7 | 12.3 |
| Ix (in⁴) | 170 | 204 | 199 | 238 |
| Sx (in³) | 32.4 | 33.4 | 29.0 | 38.6 |
| Zx (in³) | 36.6 | 37.2 | 33.2 | 43.1 |
| ry (in) | 1.37 | 1.51 | 1.04 | 1.52 |
The W12x26 offers the best Ix-per-pound ratio in this group: 204/26 = 7.85 in⁴ per lb/ft, compared to 5.67 for the W10x30 and 9.05 for the W14x22. However, the W14x22's lower ry (1.04 in) means it is more susceptible to lateral-torsional buckling, requiring closer brace spacing.
Run This Calculation
Beam Capacity Calculator -- check W12x26 bending, shear, and LTB capacity per AISC 360, AS 4100, EN 1993, or CSA S16.
Beam Deflection Calculator -- calculate deflection for W12x26 under point loads, UDL, or combined loading.
Column Capacity Calculator -- check W12x26 as a column with axial compression and KL/r slenderness.
Related Pages
- Section Properties Database
- W-Shape Beam Sizes -- Complete Table
- Steel Beam Load Tables
- Steel Grades Reference
- Beam Span Screener
- Rebar Development Length
- Concrete Footing Design
- steel grade reference (A992, A572)
- W14x48 section properties
- W10x49 section properties
- W8x31 section properties
- W10x26 section properties
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