3105 aluminum
Alloy identity, temper and thickness limits, coated-sheet systems, forming and service boundaries for 3105 aluminum.
Tags: materials, aluminum, sheet-metal, coated-coil
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Identify the alloy before the coating or application
The Australian Aluminium Council's rolled-products manual lists 95–145 MPa tensile strength and 19% minimum elongation for 3105-O over 0.65 through 1.2 mm. At that gauge, H14 lists 150–200 MPa and 2% minimum elongation. Use the table's specimen basis and footnotes when comparing results. AAC rolled-product property table, p. 24
3105 is a registered wrought aluminum alloy containing manganese and magnesium. The Aluminum Association's Teal Sheets, revised December 2025, specify 0.30–0.80% manganese and 0.20–0.80% magnesium by mass. Limits include 0.60% silicon, 0.70% iron, 0.30% copper, 0.20% chromium, 0.40% zinc and 0.10% titanium, with aluminum as the remainder. These are composition limits, not a measured batch analysis. Aluminum Association 3105 registration
The same record lists 3105A and 3105B separately. For example, 3105A has a lower maximum zinc content of 0.25%. Preserve any suffix and designation system in the material callout; a similar nominal chemistry or application does not establish an approved substitution. Teal Sheets, 3105 family entries
A useful stock description also states temper, sheet/strip/coil form, thickness and tolerances, surface/coating system, applicable specification and edition, and required certification. “Roofing aluminum” or “painted 3105” leaves essential material and performance requirements unresolved.
Temper and thickness define the property claim
The Australian Aluminium Council's Rolled Products Manual, January 2024, distinguishes annealed O from strain-hardened H conditions. H14 is strain hardened only to a half-hard condition; H24 includes partial annealing. Those processing histories must remain separate even where some property ranges overlap. The designation is not a percentage thickness reduction or a guarantee of one hardness value. AAC temper definitions, pp. 9–10
Do not select forming behavior from strength alone. A harder condition can trade ductility for strength, and a single elongation value does not establish a bend radius, draw ratio or finished-part allowable. Keep product form, thickness band, test direction, gauge length and value status with each property entry. Typical data, purchase minima and structural design allowables answer different questions.
The Teal Sheets give nominal density 2.72 g/cm³ for 3105. As an original estimating example, an uncoated nominal 1,000 × 500 × 2 mm sheet has volume 0.001 m³ and estimated mass 2.72 kg using 2,720 kg/m³. Thickness/size tolerances, coatings, protective film and cutouts change actual mass. Aluminum Association nominal-density table
A coated product needs a separate specification
Elval's Coated Aluminium Sheets and Coils brochure lists 3105 among its painted-sheet/coil offerings in H42, H44, H46 and H48 conditions. It describes polyester and PVDF systems with different layer arrangements. That product range does not make all painted 3105 equivalent: specify the substrate condition, pretreatment, primer, top/back coats, thickness, color and required performance. The brochure carries printed code p.04.08; its filename's 2011 is not treated here as a printed revision date. Elval coated-sheet and coil brochure
A concrete manufacturer example is Berridge's 2024 architectural aluminum stocking sheet, which identifies 3105 H14 coil/flat sheet in nominal 0.032 and 0.040 in gauges, with named PVDF resin-based finishes. Those are that supplier's product descriptions, not a universal size or coating requirement for 3105. Confirm the actual ordered construction and documentation. Berridge aluminum product sheet
Read test results with their substrate and method. Berridge's sheet includes coating adhesion and formability tests. Its humidity and salt-spray rows give 2,000 hours on Galvalume and 4,000 hours on aluminum. Do not re-label those results as bare-3105 corrosion data or assume that a paint warranty establishes structural life. Match the tested assembly and warranty conditions to the supplied product. Berridge coating-test scope, p. 2
Qualify forming on the delivered product
Use the actual temper, gauge, rolling direction, tooling and coated-face orientation in forming trials. Inspect cracking, springback, thinning, tool marks and coating adhesion as applicable. An acceptable metal bend can still fail a cosmetic or coating requirement; a visually intact coating does not establish the substrate's dimensional or fatigue performance.
For roll-formed or folded architectural parts, keep profile geometry, seams, fasteners and handling damage within the qualification. Berridge calls for suitable sheet-metal fabrication practices and corrosion-compatible component parts. Its product guidance does not supply a universal minimum bend radius for every 3105 temper or coating. Berridge fabrication and installation guidance
If the route includes heating, joining or refinishing, assess the resulting condition rather than relying solely on the incoming temper. The delivered sheet, locally heated region and completed assembly need not retain identical properties. Agree the final acceptance criteria before manufacturing.
Service, joining and release boundaries
Evaluate exposure, cleaning chemicals, temperature, moisture traps, cut edges and dissimilar-metal contacts for the actual assembly. A building-product application list is not a fluid-compatibility chart, food-contact approval, allowable pressure or structural load rating. Where welding, brazing, bonding or mechanical fastening is required, qualify that joint and its surface preparation separately from the sheet purchase.
A receiving/release record should link the lot certificate to complete alloy/temper, gauge, finish and governing requirements. For prefinished stock, retain coating identification, face orientation, handling requirements and approved appearance sample. Keep changes of alloy suffix, temper, gauge, coating supplier or thermal route visible as proposed changes to the qualified product.
Sources were reviewed November 1, 2026. The AAC manual's actual header says January 2024; the Berridge sheet carries a 2024 copyright. Upload paths and search-engine dates are not presented as new material specifications.