610UB131 AS/NZS 3679.1 Grade 300 — Australian Universal Beam Section Properties

610UB131 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) 610 mm
Flange Width (bf) 250 mm
Flange Thickness (tf) 15.5 mm
Web Thickness (tw) 9.0 mm
Cross-Sectional Area (A) 129.6 cm²
Mass 131.0 kg/m

Elastic Section Properties (Metric)

Property Strong Axis (X-X) Weak Axis (Y-Y) Unit
Moment of Inertia (I) 83,050 4,040 cm⁴
Elastic Section Modulus (S) 2,723 323 cm³
Plastic Section Modulus (Z) 3,058 496 cm³
Radius of Gyration (r) 25.31 5.58 cm

Torsional Properties

Property Value Unit
Torsional Constant (J) 76 cm⁴
Distance Between Flange Centroids (ho) 59.45 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 = 83,050 cm⁴, the strong-axis flexural stiffness is suitable for preliminary sizing of beams and beam-columns.

At 610 mm deep and 131 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 917 kN·m
Deflection Δ = 5wL⁴/(384EIx) Use Ix = 83,050 cm⁴
Torsion St. Venant = GJ/L J = 76 cm⁴
Column buckling KL/r → Fcr r_x = 25.31 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: Office floor beam — 610ub131

Scenario: Commercial office floor — typical open-plan layout with raised floor. Simply supported I-section, 11.6 m span, 2.4 m tributary width. Service loads: 4.0 kPa dead + 3.0 kPa live (16.8 kN/m total).

Given:

Step 1 — Live load deflection:

Δ_LL = 5 w_L L⁴ / (384 E Ix)

Δ_LL = 5 × 7.2 × (11590)⁴ / (384 × 200000 × 830,500,000)

Δ_LL = 10.2 mm

Step 2 — Deflection limit (L/300):

Δ_limit = L / 300 = 11590 / 300 = 38.6 mm

Step 3 — Dead + live deflection:

Δ_total = 23.8 mm

Step 4 — Design check:

✓ Live load deflection is within the L/300 limit.

Verify the design moment M*_Ed (from factored loads 1.35G + 1.5Q per AS 4100) does not exceed φMn = 826 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.