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 cm²
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 cm⁴
Elastic Section Modulus (S) 2,176 250 cm³
Plastic Section Modulus (Z) 2,477 389 cm³
Radius of Gyration (r) 21.61 4.61 cm

Torsional Properties

Property Value Unit
Torsional Constant (J) 88 cm⁴
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 cm⁴, 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 × Fy 743 kN·m
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 57,670 cm⁴
Torsion St. Venant = GJ/L J = 88 cm⁴
Column buckling KL/r → Fcr r_x = 21.61 cm

Design Notes

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:

Step 1 — Live load deflection:

Δ_LL = 5 w_L L⁴ / (384 E Ix)

Δ_LL = 5 × 22.5 × (13780)⁴ / (384 × 200000 × 576,700,000)

Δ_LL = 91.6 mm

Step 2 — Deflection limit (L/250):

Δ_limit = L / 250 = 13780 / 250 = 55.1 mm

Step 3 — Dead + live deflection:

Δ_total = 152.6 mm

Step 4 — Design check:

⚠ Live 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 φMn = 669 kN·m. Also confirm shear resistance and bearing details at the supports.

Related Resources

Design Resources


Educational reference only. Verify all section properties against the current AS 4100 Manual and mill certificates before design. Results are PRELIMINARY — NOT FOR CONSTRUCTION.