6061
The most versatile and widely used structural aluminum alloy, the 6xxx series benchmark.
Developed in 1935, 6061 is the benchmark against which other 6xxx alloys are compared. With copper content (0.15–0.40%) giving it higher strength, it is the second most commonly extruded alloy in the world after 6063.
International Nomenclature
| Standard | Designation |
|---|---|
| AA (USA) | 6061 |
| EN (Europa) | EN AW-6061 · AlMg1SiCu |
| DIN (Alemania) | AlMgSi1Cu / 3.3211 |
| ISO | AlMg1SiCu |
| JIS (Japón) | A6061 |
| BS (Reino Unido) | H20 |
Chemical Composition
| Element | Symbol | Percentage |
|---|---|---|
| Aluminum | Al | Balance |
| Magnesium | Mg | 0.80–1.20% |
| Silicon | Si | 0.40–0.80% |
| Iron | Fe | ≤0.70% |
| Copper | Cu | 0.15–0.40% |
| Chromium | Cr | 0.04–0.35% |
| Zinc | Zn | ≤0.25% |
| Titanium | Ti | ≤0.15% |
| Manganese | Mn | ≤0.15% |
Physical Properties
| Property | Value |
|---|---|
| Density | 2.70 g/cm³ |
| Melting Range | 582–652 °C |
| Thermal Conductivity | 152 W/m·K |
| Electrical Conductivity | ~43% IACS |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength (UTS) | 290–310 MPa (T6) |
| Yield Strength | 240–276 MPa (T6) |
| Elongation | 8–10% |
| Hardness | ~95 HB |
| Fatigue Strength | 97 MPa (5×10⁸ cycles) |
Key Characteristics
- The most versatile and widely used structural aluminum alloy in the world
- Precipitation-hardened (heat-treatable) for excellent strength
- Good corrosion resistance to atmosphere and seawater
- Excellent machinability, especially in T4 and T6 tempers
- Second most commonly extruded alloy worldwide (after 6063)
Compared to Similar Alloys
6061 vs 6063
Both are heat-treatable 6xxx (AlMgSi) alloys, but 6061 carries more magnesium (0.80–1.20%) and intentional copper (0.15–0.40%) for higher structural strength, while 6063 keeps copper near-zero (≤0.10%) with less magnesium, prioritizing surface finish and anodizing. In short: 6061 is the structural benchmark; 6063 is the "architectural aluminum" for visible extrusions.
| Dimension | 6061 | 6063 |
|---|---|---|
| Key alloying elements | Mg 0.80–1.20%, Si 0.40–0.80%, intentional Cu 0.15–0.40% | Mg 0.45–0.90%, Si 0.20–0.60%, Cu ≤0.10% (near-zero) |
| Strength (T6) | UTS 290–310 MPa, yield 240–276 MPa, ~95 HB | UTS 190–240 MPa, yield 160–214 MPa, ~73 HB |
| Anodizing & finish | Good, but copper slightly dulls the anodized finish | Excellent (★★★★★); smooth finishes thanks to low copper |
| Corrosion resistance | Good in atmosphere and seawater; slightly lower due to copper | Superior to 6061 thanks to its lower copper content |
| Extrudability / forming | 2nd most-extruded alloy; excellent machinability (T4/T6) | World's most-extruded alloy; complex, thin cross-sections |
| Electrical conductivity | ~43% IACS; thermal conductivity 152 W/m·K | ~53% IACS; thermal conductivity 200 W/m·K |
| Typical application | Structural: automotive, aerospace, marine, bridges | Architecture: frames, curtain walls, railings, tubing |
6061: Choose 6061 when you need the highest structural strength and hardness (UTS ~290–310 MPa, ~95 HB) for load-bearing parts in transportation, marine, or construction.
6063: Choose 6063 when surface appearance and anodizing matter, or for architectural extrusions with complex cross-sections and superior corrosion resistance.
Industries & Applications
Automotive
Structural components, chassis parts, body panels
Aerospace
Aircraft fittings, structural components, fuel tanks
Marine
Yacht construction, boat hulls, marine fittings
Construction
Bridge decks, roof structures, building frameworks
Special Notes
Developed in 1935, 6061 is the industry benchmark when structural strength is required. Copper content (0.15–0.40%) gives it higher strength than 6063 but slightly lower corrosion resistance. Common tempers: O, T4, T6, T651.
Frequently Asked Questions
What is 6061 aluminum and what is it used for?
6061 is the most versatile and widely used structural aluminum alloy in the world and the benchmark of the 6xxx series (AlMg1SiCu, EN AW-6061). Developed in 1935, it delivers 290–310 MPa tensile strength in the T6 temper. It is used in automotive structural and chassis components, aerospace fittings and fuel tanks, yacht construction and boat hulls, and construction structures such as bridge decks and building frameworks.
What are the alloying elements of 6061 and what do they do?
6061 is an aluminum-magnesium-silicon alloy: magnesium (0.80–1.20%) and silicon (0.40–0.80%) form the Mg2Si precipitate responsible for heat-treatment hardening. Copper (0.15–0.40%) adds extra strength, while chromium (0.04–0.35%) improves toughness and corrosion resistance. It also contains Fe (≤0.70%), Zn (≤0.25%), Ti (≤0.15%), and Mn (≤0.15%) as secondary elements.
Is 6061 heat-treatable? What tempers are available?
Yes, 6061 is precipitation-hardened (heat-treatable), leveraging the Mg2Si precipitate. Common tempers are O (annealed), T4 (solution heat-treated and naturally aged), T6 and T651 (solution heat-treated and artificially aged). In the T6 temper it reaches peak strength: 290–310 MPa tensile, 240–276 MPa yield, and a hardness near 95 HB.
What machinability, weldability and corrosion resistance does 6061 offer?
6061 offers excellent machinability, especially in the T4 and T6 tempers, and good corrosion resistance to atmosphere and seawater, making it suitable for marine applications. As a heat-treatable 6xxx alloy it is weldable by conventional methods; however, the heat-affected zone loses some of its precipitation hardening, so post-weld heat treatment or aging is typically needed to restore full joint strength.
How does 6061 differ from 6063?
6061 and 6063 are the two most-extruded 6xxx alloys in the world, with 6061 being second after 6063. The key difference is 6061's copper content (0.15–0.40%), which gives it higher structural strength at the cost of slightly lower corrosion resistance. That is why 6061 is the benchmark when structural strength is required, while 6063 is preferred for architectural profiles where surface finish and extrudability matter most.
Can Transformación Puebla make 6061 from primary or recycled-wheel (rin) stock?
It is important to clarify that 6061 is a wrought/extrusion alloy of the 6xxx series, not a casting alloy. Transformación Puebla is a foundry that produces casting alloys from primary aluminum and recycled wheels (car rims cast in A356.2); 6061 is formed by extrusion and rolling, not by casting. For structural needs in cast form, the right choice is a casting alloy from our catalog rather than wrought 6061.
Need 6061?
We manufacture this alloy in ingots, donuts, and bars to your exact specifications.