Einführung
3105 aluminum is the 3000-series alloy that sits between 3003 and 5052 — it adds a small amount of magnesium to the Aluminium-manganese base, gaining a modest strength bump over 3003 while keeping the same basic formability, corrosion resistance, and weldability. It is widely used in construction, roofing, siding, and HVAC ductwork. This guide covers where 3105 is a good fit, when to step up to 5052, and what to check before ordering.
Chemische Zusammensetzung
3105 is an Al-Mn-Mg system with low copper and controlled impurities:
- Manganese: 0.3–0.8%
- Magnesium: 0.2–0.8%
- Copper: ≤0.3%
- Iron: ≤0.7%
- Silicon: ≤0.6%
- Zinc: ≤0.4%
- Chromium: ≤0.2%
- Titanium: ≤0.1%
- Balance: Aluminum
Wichtige Eigenschaften
Strength and Work Hardening
3105 is non-heat-treatable — all strength gains come from strain hardening (cold working). In the H14 temper (half-hard), tensile strength is approximately 150–200 MPa with yield strength around 130–160 MPa. In the H19 temper (full-hard), tensile strength reaches approximately 215–260 MPa. The strength bump over 3003 is modest (typically 10–20 MPa) but meaningful in thin-gauge applications where every MPa counts.
Verformbarkeit
3105 bends, roll-forms, and stamps well across most common tempers. The alloy is commonly produced in sheet and coil for continuous forming operations — roofing panels, siding profiles, and gutter systems are typical production targets. Deep drawing is better in softer tempers (H12/H14); tight-radius bending should be checked in H19.
Korrosionsbeständigkeit
3105 provides good resistance to general atmospheric corrosion, mild chemical exposure, and moisture. It performs well outdoors in architectural and construction applications without cladding — the low copper content keeps the corrosion risk manageable. It is not rated for direct saltwater immersion.
Schweißeignung
3105 welds readily with standard aluminum processes — GTAW (TIG), GMAW (MIG), and resistance welding all work. Filler alloys 4043 or 1100 are commonly used, and post-weld strength in the HAZ is lower than the cold-worked base metal (as expected for any non-heat-treatable alloy).
Häufige Temperamente
- H14: Half-hard (strain-hardened to 1/2 hard). The most commonly specified temper for general sheet metal and construction applications.
- H19: Full-hard (strain-hardened to full hard). Selected when maximum strength from cold working is needed, for example in thin-gauge roll-formed profiles.
- H24: Half-hard and partially annealed. Provides slightly higher ductility than H14 at the same strength level — useful when forming is more demanding.
3105 vs. Other Alloys
3105 vs. 3003
3003 is the baseline aluminum-manganese alloy. 3105 adds magnesium, gaining roughly 10–20 MPa in tensile strength across equivalent tempers. The trade-off is minimal — formability and corrosion resistance are nearly identical. Choose 3105 when the slightly higher strength helps reduce gauge thickness or meet a wind-load requirement; choose 3003 when absolute maximum availability and lowest cost matter more.
3105 vs. 5052
5052 is the step up: higher tensile strength (~230 MPa in H34 vs. 3105-H14’s ~170 MPa), better corrosion resistance, and full marine service capability — but at a higher cost. 3105 covers general construction and architectural applications; 5052 becomes the right choice when structural loads are higher or the environment is more aggressive.
3105 vs. 1100
1100 is commercially pure aluminum — maximum corrosion resistance and formability, minimal strength. 3105 is the higher-strength option in the 3xxx range while retaining most of 1100’s corrosion performance. For architectural sheet where some structural stiffness is needed, 3105 is the more practical grade.
Go/No-Go Limits
Use this quick reference to decide whether 3105 fits your application.
Go — use 3105 when:
- Moderate strength with good formability and atmospheric corrosion resistance is the combination needed — 3105 covers the window between 3003 and 5052 at a competitive cost. Typical applications: roofing sheets, siding panels, gutter systems, air ducts.
- Continuous roll-forming or stamping of coil stock is the production method — 3105 is widely available in coil form with consistent gauge and temper control. Typical applications: architectural profiles, closures, trim components.
- Welding is required and strength after welding does not need to match the cold-worked base metal — 3105 welds with standard filler alloys and common processes.
No-Go — do not use 3105 when:
- Tensile strength above 200 MPa in the delivered condition is a requirement — switch to 5052-H32/H34 or consider 6061-T6 for machined structural parts.
- Direct saltwater immersion or severe chemical exposure is expected — 5052, 5083, or 6061 with protective coating are more appropriate for marine and chemical-service environments.
- Heat treatment to increase strength is part of the manufacturing plan — 3105 is non-heat-treatable; all strength comes from cold working, and annealing will reduce it.
- Anodizing quality is a cosmetic or specification requirement — 3xxx alloys produce a less uniform anodized surface than 6xxx alloys; confirm the appearance standard before selecting 3105 for anodized parts.
Anwendungen
The Go/No-Go criteria above cover selection logic. The list below maps specific systems where 3105 is standard practice:
- Construction — roofing panels, wall cladding, siding, flashing, gutter systems
- HVAC — air ducts, ventilation components, heat-exchanger fins (in thinner gauges)
- Architectural — decorative trim, cove moldings, ceiling panels
- General sheet metal — enclosures, cabinets, panels, signage backers
Schlussfolgerung
3105 aluminum is the practical 3000-series upgrade from 3003 — it adds a modest strength boost from magnesium while keeping the same formability, corrosion resistance, and weldability that make the 3xxx family the default choice for construction and architectural sheet metal. The limits are real: it cannot be heat-treated, it is not marine-grade without coating, and its anodizing appearance is less uniform than 6xxx alloys.
Linsy Aluminum supplies 3105 in sheet, coil, and custom-dimension plate, with low-MOQ production available for non-stock specifications. Full MTC documentation accompanies every order, and SGS testing for composition and mechanical properties is available on request. If the project requires a specific temper, gauge, or coil width, send the specification for a technical review.
Häufig gestellte Fragen
Was ist der Unterschied zwischen Aluminium 3003 und 3105?
3105 contains magnesium (0.2–0.8%) while 3003 does not. This addition increases tensile strength by roughly 10–20 MPa in equivalent tempers. Formability, corrosion resistance, and weldability are nearly identical — the choice usually hinges on whether the extra strength helps meet a structural or gauge-reduction target.
Can 3105 aluminum be welded?
Yes — 3105 is readily weldable with GTAW (TIG) and GMAW (MIG). Filler alloys 4043 or 1100 are commonly used. As with all non-heat-treatable alloys, the cold-worked strength is reduced in the heat-affected zone, so design should account for lower local strength near welds.
How does 3105 perform in outdoor environments?
3105 provides good resistance to general atmospheric corrosion and is widely used in unpainted roofing and siding applications. It is not suitable for direct saltwater immersion or chemically aggressive environments. For coastal construction, a protective coating or a move to 5052 is recommended.
Is 3105 available in coil form?
Yes — coil is the most common product form for 3105, supporting continuous roll-forming, stamping, and sheet metal fabrication lines. Standard tempers H14 and H19 are typical; custom gauge and width combinations require specification confirmation with the mill.
Can 3105 be anodized?
While technically possible, the anodized finish on 3105 is less uniform than on 6xxx-series alloys due to the manganese and magnesium content. For applications where anodizing quality is visually or functionally critical, 6061 or 6063 are stronger candidates — or specify a painted/coated finish on 3105 instead.
