W920x473 G40.21 350W — Canadian W-Shape Section Properties
Approximate equivalent of W36X318 per AISC A6. Approx. equivalent of W36X318. Verify against CISC Handbook.
Dimensions (Metric)
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 970.3 | mm |
| Flange Width (bf) | 315.0 | mm |
| Flange Thickness (tf) | 54.1 | mm |
| Web Thickness (tw) | 30.0 | mm |
| Cross-Sectional Area (A) | 602.6 | cmÃÂò |
| Mass | 473.2 | kg/m |
Elastic Section Properties (Metric)
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 882,408 | 28,387 | cm⁴ |
| Elastic Section Modulus (S) | 18,190 | 1,803 | cmÃÂó |
| Plastic Section Modulus (Z) | 21,303 | 2,884 | cmÃÂó |
| Radius of Gyration (r) | 38.35 | 6.86 | cm |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 4,092 | cm⁴ |
| Warping Constant (Cw) | 59,607,000 | cm⁶ |
| Distance Between Flange Centroids (ho) | 91.69 | cm |
| Effective Radius (rts) | 8.46 | cm |
Imperial Reference
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 38.20 | in |
| Flange Width (bf) | 12.40 | in |
| Area (A) | 93.40 | inÃÂò |
| Weight | 318 | lb/ft |
Section Profile Summary
A wide flange with parallel flange faces — makes bolted and welded connections straightforward to detail. At Ix = 882,408 cm⁴, the strong-axis stiffness places it in the heavy beam category for preliminary sizing.
At 970.3 mm deep and 473.2 kg/m, this is a heavy section for primary framing — transfer beams, long-span roof girders, and major bridge stringers.
Key Design Checks (CSA S16)
| Check | Formula | This Section |
|---|---|---|
| Plastic moment | Mp = Zx × Fy | 7,456 kNÃÂ÷m |
| Deflection | Δ = 5wL⁴/(384EIx) | Use Ix = 882,408 cm⁴ |
| Torsion | St. Venant = GJ/L | J = 4,092 cm⁴ |
| Column buckling | KL/r → Fcr | r_x = 38.35 cm |
Design Notes
- Compactness: Most W-shapes in ASTM A992 satisfy the compact limits in CSA S16 Table B4.1b for flexure (λ ≤ λp). This allows full plastic moment Mp development before local buckling occurs.
- Flange local buckling (FLB): The flange slenderness ratio bf/2tf is compared against λpf = 0.38√(E/Fy) ≈ 9.0 for compact sections.
- Web local buckling (WLB): h/tw is checked against λpw = 3.76√(E/Fy) ≈ 72 for flexure, and a more restrictive limit for uniform compression.
- Lateral-torsional buckling (LTB): Lp ≈ 288.6 cm (plastic limit). For unbraced lengths ≤ Lp, the full plastic moment is available. Between Lp and Lr, linear interpolation per CSA S16 Eq. F2-2 applies.
Verification (CSA S16): All designs using this section must be verified by a licensed Professional Engineer. Before finalizing member selection, check beam-column interaction (P-M), lateral-torsional buckling, serviceability deflections, and all connection limit states. See Engineering Disclaimer.
Worked Example: School classroom beam — w920x473
Scenario: School building — tighter deflection limit for suspended ceiling integrity. Simply supported wide flange, 24.3 m span, 2.4 m tributary width. Service loads: 3.5 kPa dead + 3.0 kPa live (15.6 kN/m total).
Given:
- Span L = 24258 mm (24.3 m)
- Total service load w = 15.6 kN/m
- Live load portion w_L = 7.2 kN/m
- Section w920x473: Ix = 8824.1 × 10⁶ mm⁴, Sx = 18,190,000 mm³, Zx = 21,303,000 mm³
- Steel: fy = 350 MPa, E = 200,000 MPa
- Design moment resistance: φMn = 0.9 × Zx × fy = 6,710 kNÃÂ÷m
Step 1 — Live load deflection:
Δ_LL = 5 w_L L⁴ / (384 E Ix)
Δ_LL = 5 × 7.2 × (24258)⁴ / (384 × 200000 × 8,824,080,000)
Δ_LL = 18.4 mm
Step 2 — Deflection limit (L/360):
Δ_limit = L / 360 = 24258 / 360 = 67.4 mm
Step 3 — Dead + live deflection:
Δ_total = 39.9 mm
Step 4 — Design check:
✓ Live load deflection is within the L/360 limit.
Verify the design moment M*_Ed (from factored loads 1.35G + 1.5Q per CSA S16) does not exceed φMn = 6,710 kNÃÂ÷m. Also confirm shear resistance and bearing details at the supports.
Related Resources
- Steel Beam Capacity Calculator
- Column Capacity Calculator
- Beam Deflection Calculator
- Section Properties Calculator
- Steel Grades Reference
- Section Comparison Tool
Design Resources
- Section Properties Lookup — Compare with similar sections
- Steel Beam Sizes Reference — Standard beam dimensions
Educational reference only. Verify all section properties against the current CSA S16 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.