Quick picker: 6061 or 7075?
Both are heat-treatable aluminium alloys that machine well, but they are optimised for different jobs. Choose 6061 for the majority of general-purpose parts — frames, brackets, enclosures, plates and welded assemblies — where good all-round strength, corrosion resistance, finish and low cost matter. Choose 7075 when maximum strength and stiffness at low weight are the design drivers, such as aerospace and high-performance components, and you do not need to weld the part.
Strength and mechanical properties
The gap is large. In the common T6 temper, published values are:
| Property | 6061-T6 | 7075-T6 |
|---|---|---|
| Ultimate tensile strength | ~310 MPa (45 ksi) | ~572 MPa (83 ksi) |
| Yield strength | ~276 MPa (40 ksi) | ~503 MPa (73 ksi) |
| Elongation at break | 12–17% | 7–11% |
| Density | ~2.70 g/cm³ | ~2.81 g/cm³ |
| Hardness (Brinell) | ~95 HB | ~150 HB |
7075 is roughly 1.8 times stronger in yield and also stiffer and harder, which is why it resists permanent deformation under high loads. The trade-off is lower ductility — it elongates less before failing — so 6061 is more forgiving where some forming or impact tolerance is needed.
Corrosion resistance and welding
- 6061 offers good general corrosion resistance and welds readily with TIG or MIG using 4043 or 5356 filler, making it the standard for welded frames and structures.
- 7075 has somewhat lower corrosion resistance due to its high zinc and copper content and is generally not recommended for welding because it is prone to hot cracking and loses strength near the weld. It is commonly supplied in plate for machined, non-welded parts.
For 7075 parts used in corrosive environments, a protective finish such as anodising or conversion coating is advisable. For outdoor or marine structures that must be welded, 6061 (or 5052/6063) is the safer choice.
Machinability and anodising
- 6061-T6 is rated excellent to machine: it cuts cleanly at high feed rates, produces good surface finish and is forgiving on tooling — one reason it is the most popular CNC aluminium.
- 7075-T6 is rated good to machine. It is harder and can generate more tool wear, but it holds tight tolerances and fine features well because it deflects less.
- Anodising: 6061 takes clear and coloured anodising more evenly. 7075 can anodise but often appears darker and less uniform, so when a consistent cosmetic colour is critical, 6061 is preferred. See our anodising guide.
Cost and weight
Published 2026 material prices put 6061-T6 at roughly $3–5/lb ($7–11/kg) and 7075-T6 at about $6–10/lb ($13–22/kg) — 7075 commonly runs around twice the material cost. Combined with slightly slower machining, 7075 parts are more expensive unless the strength is genuinely needed. Densities are close, so there is no meaningful weight saving between the two alloys themselves; the weight advantage of 7075 comes from using thinner sections to carry the same load.
Where each alloy is used
- 6061-T6: structural frames, brackets, mounts, base plates, fixtures, automotive components, furniture, heat sinks, enclosures and welded assemblies — the economical default for aluminium CNC parts.
- 7075-T6: aerospace structures and wing components, high-strength brackets and fittings, mould and tooling plates, defence parts, bicycle and motorsport components, rock-climbing gear and other high-stress, lightweight parts.
If your part is not clearly in the high-stress category, 6061 will usually meet the requirement at lower cost and with better finishing. Send your drawing and load requirements and we will confirm the most suitable — and most economical — alloy.
Frequently asked questions
Which is stronger, 6061 or 7075 aluminum?
7075-T6 is significantly stronger: yield strength about 503 MPa vs 276 MPa for 6061-T6, and tensile strength about 572 MPa vs 310 MPa. For highly loaded, lightweight parts 7075 is the usual choice.
Is 7075 worth the extra cost over 6061?
Only when strength or fatigue drives the design. 7075 costs roughly twice as much and is harder to weld and anodise. For general structural parts 6061 is the better value.
Which anodises better?
6061 anodises more consistently and takes clear and coloured finishes more evenly. 7075 can look darker and less uniform due to its zinc and copper content.