Alloys / 2024-T351
2024-T351 Aluminum
Specified for fatigue life on parts that flex over thousands of cycles, not for static strength alone. Corrodes badly if left bare.
What it is
2000 series, aluminum-copper-magnesium. T351: solution heat treated, stress relieved by stretching, naturally aged. Chosen for stable fatigue behaviour rather than peak strength.
Machining
Machines well and holds a clean finish, similar in feeds and speeds to 7075. Fixture it the same way, expecting a strong, springy cut rather than a soft one.
Finishing and joining
Does not weld and corrodes quickly without a coating, so a bare 2024 part in service is a mistake, not a design choice. Anodize or chem film is close to mandatory, and either runs less evenly than on 6061.
Where it turns up
- Fatigue-critical structural parts
- Aircraft-style skins and ribs machined from plate
- Parts that flex repeatedly rather than carrying one static load
Read further
- What the fatigue trade-off actually buys youRead the guide
- Chem film against anodize when both are on the tableRead the guide
At a glance
| Yield strength | 325 MPa |
| Density | 2.78 g/cm³ |
| Weldability | 1 / 5 |
| Anodizing | 2 / 5 |
| Corrosion resistance | 1 / 5 |
| Strength for weight | 4 / 5 |
| Stays flat | 2 / 5 |
| Machinability | 4 / 5 |
Scores run 1 to 5, editorial judgements for comparison, not measured values. Yield is a typical published figure for this temper, not a guarantee for your lot.
Full property table for all alloys: alloy selector.
Questions
Is 2024-T351 weldable?
Not with conventional welding processes. 2024 is prone to cracking or loses most of its strength in the heat-affected zone, so a welded assembly needs a different alloy for that joint.
Does 2024-T351 anodize evenly?
Not reliably. Expect a less even, sometimes darker or patchier result than 6061 in the same anodizing tank, so treat any anodized finish on this alloy as functional rather than cosmetic.