530UB138 AS/NZS 3679.1 Grade 300 — Australian Universal Beam Section Properties
530UB138 is an Australian UB (Universal Beam) per AS/NZS 3679.1 hot-rolled structural steel section. Standard Australian UB dimensions. Verify against Liberty OneSteel / InfraBuild section catalog.
Dimensions (Metric)
| Property | Value | Unit |
|---|---|---|
| Depth (d) | 530 | mm |
| Flange Width (bf) | 210 | mm |
| Flange Thickness (tf) | 17.0 | mm |
| Web Thickness (tw) | 10.5 | mm |
| Cross-Sectional Area (A) | 123.5 | cmÃÂò |
| Mass | 138.0 | kg/m |
Elastic Section Properties (Metric)
| Property | Strong Axis (X-X) | Weak Axis (Y-Y) | Unit |
|---|---|---|---|
| Moment of Inertia (I) | 57,670 | 2,629 | cmâÃÂô |
| Elastic Section Modulus (S) | 2,176 | 250 | cmÃÂó |
| Plastic Section Modulus (Z) | 2,477 | 389 | cmÃÂó |
| Radius of Gyration (r) | 21.61 | 4.61 | cm |
Torsional Properties
| Property | Value | Unit |
|---|---|---|
| Torsional Constant (J) | 88 | cmâÃÂô |
| Distance Between Flange Centroids (ho) | 51.30 | cm |
Section Profile Summary
This is a standard hot-rolled I-section profile covered by AS 4100. The tabulated section properties are computed from the nominal dimensions per the governing material standard. With Ix = 57,670 cmâÃÂô, the strong-axis flexural stiffness is suitable for preliminary sizing of beams and beam-columns.
At 530 mm deep and 138 kg/m, this is a heavy section for primary framing — transfer beams, long-span roof girders, and major bridge stringers.
Key Design Checks (AS 4100)
| Check | Formula | This Section |
|---|---|---|
| Plastic moment | Mp = Zx ÃÂàFy | 743 kNÃÂ÷m |
| Deflection | ÃÂà= 5wLâÃÂô/(384EIx) | Use Ix = 57,670 cmâÃÂô |
| Torsion | St. Venant = GJ/L | J = 88 cmâÃÂô |
| Column buckling | KL/r âÃÂàFcr | r_x = 21.61 cm |
Design Notes
- Compactness: Verify flange and web slenderness against AS 4100 Table B4.1 classification limits for the governing load case (pure compression, pure flexure, or combined).
- Combined loading: For members under simultaneous axial force and bending, use the interaction equations in AS 4100 Section H. The governing equation depends on the ratio of required to available axial strength.
- Connection limit states: Check bolt bearing, tear-out, block shear, and weld strength at all connections. The governing connection limit state often controls the member size selection.
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: Industrial floor beam — 530ub138
Scenario: Light industrial floor — forklift traffic and storage considerations. Simply supported I-section, 13.8 m span, 3 m tributary width. Service loads: 5.0 kPa dead + 7.5 kPa live (37.5 kN/m total).
Given:
- Span L = 13780 mm (13.8 m)
- Total service load w = 37.5 kN/m
- Live load portion w_L = 22.5 kN/m
- Section 530ub138: Ix = 576.7 ÃÂà10âÃÂö mmâÃÂô, Sx = 2,176,000 mmÃÂó, Zx = 2,477,000 mmÃÂó
- Steel: fy = 300 MPa, E = 200,000 MPa
- Design moment resistance: ÃÂÃÂMn = 0.9 ÃÂàZx ÃÂàfy = 669 kNÃÂ÷m
Step 1 — Live load deflection:
ÃÂÃÂ_LL = 5 w_L LâÃÂô / (384 E Ix)
ÃÂÃÂ_LL = 5 ÃÂà22.5 ÃÂà(13780)âÃÂô / (384 ÃÂà200000 ÃÂà576,700,000)
ÃÂÃÂ_LL = 91.6 mm
Step 2 — Deflection limit (L/250):
ÃÂÃÂ_limit = L / 250 = 13780 / 250 = 55.1 mm
Step 3 — Dead + live deflection:
ÃÂÃÂ_total = 152.6 mm
Step 4 — Design check:
âÃÂàLive load deflection exceeds L/250 — 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 ÃÂÃÂMn = 669 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.