What is the difference between 7068 and 6061?
7068 aluminum alloy has higher strength and hardness than 6061, but 6061 offers better workability and corrosion resistance.
6061 is a versatile and cost-effective alloy, ideal for everyday use, while 7068 is an ultra-high-strength material designed for applications that require extremely high performance - even if this means higher costs and more complex processing.
7068 and 6061 Aluminum Key Differences
| Property | 6061 | 7068 |
| Series | 6000 (Mg/Si) | 7000 (Zn/Mg/Cu) |
| Strength | Moderate | Extremely High |
| Corrosion | Excellent | Poor (requires coating) |
| Weldability | Good | Poor |
| Cost | Lower | Higher |
| Applications | General-purpose, structural | High-stress, aerospace/military |
Choosing 6061 achieves a balance of performance, corrosion resistance, and weldability. When ultimate strength is critical and other factors (cost, corrosion resistance) can be compromised, choose 7068.
7068 vs 6061 Aluminum Composition and Alloying Elements
| Alloy | Series | Primary Alloying Elements | Key Traits |
| 6061 | 6000 Series | Magnesium (0.8–1.2%), Silicon (0.4–0.8%), Copper (0.15–0.4%), Chromium | Balanced strength, weldability, and corrosion resistance. |
| 7068 | 7000 Series | Zinc (7.5–8.5%), Magnesium (2.5–3.5%), Copper (1.6–2.4%) | Exceptionally high strength due to zinc dominance. |
7068 vs 6061 Aluminum Mechanical Properties
| Property | 6061-T6 | 7068-T6511 |
| Tensile Strength | ~310 MPa (45,000 psi) | ~641 MPa (93,000 psi) |
| Yield Strength | ~275 MPa (40,000 psi) | ~590 MPa (85,500 psi) |
| Fatigue Resistance | Good, but not as high as 7068 | Superior, especially in high-stress cyclic applications, though notch sensitive |
7068 vs 6061 Aluminum Machining and Availability
6061:
It is widely available, affordable, and relatively easy to machine, weld, and finish.
Its medium strength and ease of fabrication make it the preferred material for everyday applications in automotive, construction, and consumer goods.
7068:
It is much more expensive (usually 3-4 times the cost of 6061) and less commonly available.
The higher strength comes at the cost of more challenging machining and processing requirements. Specialized techniques are often needed during manufacturing to maintain its high-strength properties.
| Property | 6061 | 7068 |
| Weldability | Easily weldable using TIG/MIG methods, but heat-affected zone may weaken. | Poor weldability due to cracking risk; generally avoided in welding designs. |
| Machinability | Softer, easier to machine with standard tools. | Harder, requires specialized tools and slower speeds. |
7068 vs 6061 Aluminum Corrosion Resistance
- 6061: Excellent resistance to atmospheric and marine corrosion, typically used in harsh environments without additional treatment.
- 7068: Poor corrosion resistance; susceptible to stress corrosion cracking if not anodized or coated.
6061 Aluminum Corrosion Resistance
6061 aluminum exhibits excellent resistance to atmospheric and marine corrosion. It is highly durable in harsh environments and often does not require additional treatment to withstand corrosion. Its natural oxide layer provides a protective barrier, making it a reliable choice for applications exposed to various environmental conditions.
7068 Aluminum Corrosion Resistance
7068 aluminum has relatively poor corrosion resistance compared to 6061. If it is not anodized or coated, it is prone to stress corrosion cracking, particularly in highly corrosive environments. Proper surface treatment is essential to enhance its corrosion resistance and ensure its longevity in demanding applications.
7068 vs 6061 Aluminum Heat Treatment
Both can be heat-treated (precipitation hardening).
- 6061: Typically solution-treated and aged to T6 condition.
- 7068: Requires precise aging (T6511) to maximize strength.
7068 vs 6061 Aluminum Cost
- 6061: Widely available and cost-effective for general-purpose applications.
- 7068: More expensive due to its specialized composition, limited to high-performance applications.
6061 Aluminum Cost
6061 aluminum is widely available and relatively cost-effective for general-purpose applications. Its abundant supply and versatile properties make it an affordable choice for industries like automotive, construction, and consumer products. As a result, it is commonly used in a variety of applications where a balance of strength, corrosion resistance, and ease of machining is required.
7068 Aluminum Cost
7068 aluminum is more expensive due to its specialized composition, which includes higher amounts of zinc, magnesium, and copper. These elements contribute to its extremely high strength but also increase production costs. As a result, 7068 is typically used only in high-performance applications, such as aerospace and military equipment, where its superior strength justifies the higher cost.
7068 vs 6061 Aluminum Applications
6061 Aluminum Applications
Used in a wide range of applications - from structural components and automotive parts to bicycle frames and general manufacturing - cost-effectiveness and ease of production are key.
7068 Aluminum Applications
Dedicated to high-performance, high-stress applications, such as aerospace components, ordnance, and even specialty products (e.g., high-performance yoyos). It can be made extremely thin yet still very strong, making it ideal for applications where every gram counts.
| Alloy | Common Uses | Advantages |
| 6061 | Automotive parts, bicycle frames, marine components, structural frames, consumer products | Suitable for applications requiring medium strength, formability, and corrosion resistance. |
| 7068 | Aerospace components, high-performance bicycles, military equipment, specialized machinery | Ideal for high-stress environments where weight reduction and extremely high strength are needed. |
