------ | ---------- | ---------------- | ------------ | | Columns | 310UB40.4 | 4 × 6.5 | 1,050 | | Rafters | 460UB67.1 | 6 × 9.2 | 3,704 | | Purlins | 150PFC17.0 | 24 × 4.8 | 1,958 | | Total | | | 6,712 kg |

Result: 6.71 tonnes total. Add 3% for connection material (end plates, stiffeners, cleats): ~6.9 tonnes order quantity.

Mass Tolerances — AS/NZS 3679.1

AS/NZS 3679.1 permits a mass tolerance of ±4% on the nominal mass per metre for individual sections. For take-off purposes:

• Use the nominal mass per metre from the section designation (e.g., 92.4 kg/m for 530UB92.4)
• For critical crane lifts, consider the upper bound (+4%) to ensure the crane is adequately sized
• For transport cost estimation, the nominal mass is sufficient — trucking rates are typically per-tonne bands

The actual mass of any individual section varies within the ±4% tolerance band due to mill rolling practice. The cross-sectional area method (Ag × 7,850) typically agrees with the nominal mass within 1–2%.

Estimating Connection Weight

Connections add 3–8% to the main member weight, depending on the framing system:

Include connection weight in the total take-off. A 50-tonne frame at 6% connection allowance requires an additional 3 tonnes of plate and angle stock.

Australian Steel Weight for Roof Purlins and Girts

Cold-formed purlins and girts are ubiquitous in Australian industrial and commercial construction. These are typically Z-section (Zeds) or C-section (Cees) members — lighter than hot-rolled PFCs and manufactured to AS/NZS 4600 (Cold-Formed Steel Structures).

Typical purlin spans for Australian portal frames (repeating):

Purlins per portal bay rule of thumb: For a 30 m wide portal frame at 1.5 m purlin spacing, expect approximately 21 purlin lines. At 7.5 m bays with Z20019 purlins (4.1 kg/m), each bay contributes 21 × 7.5 × 4.1 = 646 kg of purlin steel. Over 10 bays this is 6.5 tonnes — typically 15–20% of the total frame weight.

Girts (wall cladding rails): For an 8 m eave height building, girts at 1.2 m spacing give 7 lines per side. At 9 m bays with Z20015 girts (3.1 kg/m), each wall bay = 7 × 9.0 × 2 sides × 3.1 = 391 kg of girt steel. Bridging and sag rods add approximately 8% to the purlin and girt weight.

Steel Tonnage Benchmarks — Australian Construction

Quick-reference estimates for preliminary budgeting (includes main members, connections, purlins, girts, and bracing):

Note: kg/m² is gross floor area including all steelwork. Values are for normal soil conditions (N-class site). Add 10–15% for cyclonic regions (Regions C and D per AS/NZS 1170.2) due to heavier wind bracing requirements.

Density check for imported sections: Australian projects occasionally specify imported European or US sections. The density of structural steel is universally 7,850 kg/m³ regardless of origin, but the section mass per metre differs because of dimensional differences. Always use the AS/NZS 3679.1 database mass for locally sourced Australian steel — the nominal mass tolerances are calibrated to Australian mill practice, not European or US rolling tolerances.

Related Resources

• Australian Beam Sizes (UB/UC/PFC)
• Australian Steel Grades — AS/NZS 3679.1 Grade 300 vs 350
• Steel Beam Capacity Calculator — AS 4100
• Column Capacity Calculator — AS 4100
• Section Properties Calculator
• AS 4100 Steel Design Guide

FAQ

What density does the calculator use? Standard steel density of 7850 kg/m³ (7.85 t/m³) — consistent with AS/NZS 3679.1 and EN 10025. This is the accepted value for structural carbon steel. Stainless steel is denser at ~8000 kg/m³ and is not covered by this calculator.

Is the mass per metre the same as the section designation? Yes. Australian UB and UC sections carry their nominal mass in the designation: 530UB92.4 has a nominal mass of 92.4 kg/m, 310UB40.4 has 40.4 kg/m. This is different from US W-shapes where the designation is weight in lb/ft (W12×72 = 72 lb/ft). The calculator handles both naming conventions.

Can I calculate plate weight? Yes. Enter plate width, length, and thickness in millimetres. The calculator converts to metres, computes volume, and applies the standard density. For fabrication take-offs, add a waste allowance (typically 5–15% depending on shape complexity) on top of the calculator output.

Are UB/UC the same as European IPE/HEA sections? No. UB sections (Universal Beams) are a distinct series with different dimensional proportions from European IPE beams. UC sections (Universal Columns) have heavier flanges than HEA sections of comparable depth. Always select the correct regional code — the Australian database contains AS/NZS 3679.1 sections, the European database contains EN 10365 sections.

How accurate is the calculator for crane lift planning? The calculator provides the nominal steel weight. For crane sizing, the rigger should add the weight of: (a) lifting beam/spreader bar, (b) shackles and slings, (c) any attached cleats or brackets that were shop-welded, and (d) the upper-bound mass tolerance (+4%). The total lift weight is typically 110–120% of the nominal steel weight.

Does the calculator account for galvanising weight? No. Hot-dip galvanising adds approximately 3–7% to the section weight, depending on the section size and coating thickness per AS/NZS 4680. For galvanised steel, multiply the calculator output by 1.05 to approximate the coated weight. For precise values, use the coating mass from the galvaniser's certificate.

Design Resources

• Section Dimensions and Properties — Compare with similar sections
• Steel Beam Sizes Reference — Standard beam dimensions
• AS 4100 Load Combinations — Factored design loads

Educational reference only. Steel weight estimates are preliminary. Verify section masses against the current AS/NZS 3679.1 standard and mill certificates before procurement. Results are PRELIMINARY — NOT FOR CONSTRUCTION.