200PFC AS/NZS 3679.1 Grade 300 — Australian Parallel Flange Channel Section Properties
200PFC is an Australian PFC (Parallel Flange Channel) per AS/NZS 3679.1 hot-rolled structural steel section. Standard Australian PFC dimensions. Verify against Liberty OneSteel / InfraBuild section catalog.
Dimensions (Metric)
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 200 | mm |
| Flange Width (bf) | 75 | mm |
| Flange Thickness (tf) | 10.5 | mm |
| Web Thickness (tw) | 6.0 | mm |
| Cross-Sectional Area (A) | 26.5 | cm² |
| Mass | 26.0 | kg/m |
Elastic Section Properties (Metric)
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 1,702 | 74 | cm⁴ |
| Elastic Section Modulus (S) | 170 | 20 | cm³ |
| Plastic Section Modulus (Z) | 197 | 31 | cm³ |
| Radius of Gyration (r) | 8.02 | 1.67 | cm |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 7 | cm⁴ |
| Distance Between Flange Centroids (ho) | 18.95 | cm |
Section Profile Summary
The shear center of a channel lies outside the web (distance e₀ from the web face). Loads applied to the top flange produce torsion unless the load plane passes through the shear center. For AS 4100 flexural design, lateral-torsional buckling must be checked with the warping constant Cw.
At 200 mm deep, this is a mid-range section for secondary beams, roof purlins, and bracing in standard framing.
Key Design Checks (AS 4100)
| Check | Formula | This Section |
|---|---|---|
| Plastic moment | Mp = Zx × Fy | 59 kNÃÂ÷m |
| Deflection | Δ = 5wL⁴/(384EIx) | Use Ix = 1,702 cm⁴ |
| Torsion | St. Venant = GJ/L | J = 7 cm⁴ |
| Column buckling | KL/r → Fcr | r_x = 8.02 cm |
Design Notes
- Section asymmetry: The shear center lies outside the web. Loads not applied through the shear center produce torsion. Provide intermediate torsional restraints or stiffeners when the load eccentricity is significant.
- Lateral-torsional buckling: Check Cb (moment modification factor) per AS 4100 Chapter F — channels are more sensitive to load height effects than doubly-symmetric sections.
- Web crippling at supports: For channels used as beams, bearing stiffeners may be needed at concentrated load points per AS 4100 Section J10.
Verification (AS 4100): 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: Residential floor beam — 200pfc
Scenario: Residential apartment floor — partition allowance included in dead load. Simply supported channel, 5.2 m span, 3 m tributary width. Service loads: 3.0 kPa dead + 2.0 kPa live (15.0 kN/m total).
Given:
- Span L = 5200 mm (5.2 m)
- Total service load w = 15.0 kN/m
- Live load portion w_L = 6.0 kN/m
- Section 200pfc: Ix = 17.0 × 10⁶ mm⁴, Sx = 170,000 mm³, Zx = 197,000 mm³
- Steel: fy = 300 MPa, E = 200,000 MPa
- Design moment resistance: φMn = 0.9 × Zx × fy = 53 kNÃÂ÷m
Step 1 — Live load deflection:
Δ_LL = 5 w_L L⁴ / (384 E Ix)
Δ_LL = 5 × 6.0 × (5200)⁴ / (384 × 200000 × 17,020,000)
Δ_LL = 16.8 mm
Step 2 — Deflection limit (L/360):
Δ_limit = L / 360 = 5200 / 360 = 14.4 mm
Step 3 — Dead + live deflection:
Δ_total = 42.0 mm
Step 4 — Design check:
⚠ Live load deflection exceeds L/360 — consider a deeper section, reduce tributary, or shorten the span.
Verify the design moment M*_Ed (from factored loads 1.35G + 1.5Q per AS 4100) does not exceed φMn = 53 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 AS 4100 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.