Common Aluminum Alloys for Engineering
Not all aluminum is the same. The alloy designation tells you everything about its strength, machinability, weldability, and corrosion resistance. Here’s the practical comparison for the alloys you’ll actually encounter.
Properties Comparison Table
| Property | 6061-T6 | 7075-T6 | 2024-T3 | 5052-H32 |
|---|---|---|---|---|
| Tensile Strength (ksi) | 45 | 83 | 70 | 33 |
| Yield Strength (ksi) | 40 | 73 | 50 | 28 |
| Elongation (%) | 12 | 11 | 18 | 12 |
| Hardness (Brinell) | 95 | 150 | 120 | 60 |
| Machinability | Good | Good | Good | Fair |
| Weldability | Good | Poor | Poor | Excellent |
| Corrosion Resistance | Good | Fair | Fair | Excellent |
| Anodizing | Excellent | Good | Fair | Good |
| Formability | Good | Poor | Fair | Excellent |
| Cost (relative) | $ | $$$ | $$ | $ |
When to Use Each Alloy
6061-T6 — The Default Choice
If you’re not sure which aluminum to use, start with 6061-T6. It’s the most versatile alloy with good strength, excellent machinability, good weldability, and great corrosion resistance. It anodizes beautifully.
- Structural frames and brackets
- Machine parts and fixtures
- Automotive and marine components
- Consumer products (enclosures, housings)
7075-T6 — Maximum Strength
Nearly as strong as many steels at one-third the weight. Used where strength-to-weight ratio is critical. Do not weld 7075 — it cracks. Fasteners or adhesive bonding only.
- Aerospace structures (wing spars, fuselage frames)
- High-performance bicycle frames
- Climbing equipment
- Mold tooling (when weight matters)
2024-T3 — Aerospace Workhorse
The classic aircraft aluminum. Higher fatigue resistance than 7075, which matters for pressurized fuselages and wing skins. Poor corrosion resistance — almost always clad (Alclad) with pure aluminum layer.
- Aircraft fuselage and wing skins
- Truck wheels
- Scientific instruments
5052-H32 — Best for Sheet Metal & Welding
The go-to for sheet metal work, especially marine applications. Excellent corrosion resistance, great formability, welds easily. Not heat-treatable — strength comes from work hardening (H temper).
- Boat hulls and marine components
- Fuel tanks
- Sheet metal enclosures
- Chemical processing equipment
Alloy Series Quick Reference
| Series | Alloying Element | Key Characteristic | Common Alloys |
|---|---|---|---|
| 1xxx | Pure aluminum (99%+) | Highest conductivity, very soft | 1100, 1350 |
| 2xxx | Copper | High strength, poor corrosion | 2024, 2011, 2219 |
| 3xxx | Manganese | Moderate strength, good formability | 3003, 3004 |
| 5xxx | Magnesium | Best corrosion resistance, weldable | 5052, 5083, 5086 |
| 6xxx | Magnesium + Silicon | Versatile, heat-treatable, weldable | 6061, 6063, 6082 |
| 7xxx | Zinc | Highest strength, NOT weldable | 7075, 7050, 7068 |
Temper Designations
- -O — Annealed (softest, most formable)
- -T3 — Solution heat treated + cold worked
- -T4 — Solution heat treated + naturally aged
- -T6 — Solution heat treated + artificially aged (strongest standard temper)
- -H32 — Strain hardened + stabilized (for non-heat-treatable alloys like 5052)
Related: Galvanic Compatibility | Machinability of Metals | Surface Finish Guide