The verdict
Choose 6061-T6 when you need a cost-effective, corrosion-resistant, weldable alloy for general structural, fixture, and machined parts. Choose 7075-T6 when strength-to-weight is the priority and the part is highly loaded or fatigue-driven — aircraft, motorsport, and high-stress fittings — and you can join it mechanically rather than welding. In short: 6061 for value and versatility, 7075 for maximum strength.
Side-by-side data
| Property | 6061-T6 | 7075-T6 |
|---|---|---|
| Category | Aluminum | Aluminum |
| Density (g/cm³) | 2.7 | 2.81 |
| Tensile strength (MPa) | 310 | 572 |
| Yield strength (MPa) | 276 | 503 |
| Elongation (%) | 12 | 11 |
| Hardness | 95 HB | 150 HB |
| Max service temp (°C) | 170 | 130 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 167 | 130 |
| Typically used for | All-round structural & machined parts — the default aluminum | High-strength aerospace & high-stress parts |
Which should you choose?
Choose 6061-T6 if…
- The part will be welded — 6061 fusion-welds reliably, while 7075 effectively cannot.
- You want good bare corrosion resistance, including marine and outdoor service, without mandatory coatings.
- Cost and availability matter — 6061 is cheaper and stocked in extrusions, sheet, plate, bar, and tube.
- Loads are moderate: brackets, frames, enclosures, fixtures, general machined parts.
- You need extruded profiles or complex shapes — 7075 is rarely extruded.
Choose 7075-T6 if…
- You're weight-limited and load-critical — 7075 offers far higher yield and tensile strength and the best strength-to-weight of common aluminums.
- The part is fatigue- or stress-driven: aircraft spars and fittings, motorsport uprights, high-stress structural brackets.
- The component is machined from plate or bar, not welded — joining will be bolted, riveted, or bonded.
- You can absorb higher material cost and tighter supply for the performance gain.
- Service is benign or protected — you'll anodize, alclad, or coat to offset its weaker corrosion behavior.
Key differences that matter
- Strength: 7075-T6 is substantially stronger (roughly double the yield of 6061-T6), which is the main reason to pay for it; 6061-T6 is plenty for general structures.
- Weldability: 6061 fusion-welds well; 7075 is considered non-weldable by fusion (hot cracking, severe strength loss), so 7075 assemblies are bolted, riveted, or bonded.
- Corrosion: 6061 resists corrosion well; 7075's zinc-rich chemistry is more susceptible, including stress-corrosion cracking, often requiring anodizing, alclad, or coatings.
- Machinability: both machine well, but 7075 typically yields cleaner finishes and chip control; 6061 can be gummier without sharp tooling.
- Cost & availability: 6061 is cheaper and far more widely stocked, especially as extrusions; 7075 is premium-priced and mostly plate/bar.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is 6061-T6 stronger than 7075-T6?
No. 7075-T6 is significantly stronger — its yield strength is roughly twice that of 6061-T6 — which is why it's favored for highly loaded, weight-critical parts. 6061-T6 is still strong enough for most general structural and machined work.
Which is cheaper, 6061 or 7075?
6061-T6 is cheaper, often by a meaningful margin, and is stocked in many more forms and sizes — including extruded profiles. 7075-T6 carries a premium and is mainly available as plate and bar.
Can you weld 7075-T6?
Not practically by fusion welding — it's prone to hot cracking and loses a large fraction of its strength in the heat-affected zone. 7075 parts are normally joined mechanically (bolts, rivets) or adhesively bonded. If you must weld, choose 6061.
Can both be anodized and machined?
Yes to both. Both alloys machine well, with 7075 generally giving cleaner finishes. Both anodize, but 6061 typically produces a more uniform, cosmetically consistent anodized appearance; 7075 is often anodized mainly for corrosion protection.
Does 7075 have worse corrosion resistance?
Yes. 7075's high zinc content makes it more susceptible to corrosion and stress-corrosion cracking than 6061. It's commonly protected by anodizing, alclad layers, or coatings, especially in marine or outdoor environments where 6061 may be left bare.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.