2025-T6 Aluminum
A 2000-series Al-Cu-Si-Mn alloy, for forged parts
Typical values for the temper in the title
2025 is an aluminum-copper alloy with silicon and manganese, developed specifically for forging. Unlike most 2000-series alloys it contains almost no magnesium. In T6 its tensile strength is about 400 MPa, with good ductility.
For years it was used to forge propellers and propeller hubs, and other forged aerospace parts. Today most new uses have moved to 2014, but it still appears in specifications and existing parts.
Mechanical and physical properties
| Property | Value | Note |
|---|---|---|
| Tensile strength Rm | 400 MPa | |
| Yield strength Rp0.2 | 310 MPa | |
| Elongation A | 19% | |
| Hardness | 110 HB | |
| Modulus of elasticity E | 72 GPa | |
| Density ρ | 2.82 g/cm³ | |
| Machinability | 60% | relative rating in the site database |
Chemical composition (wt %)
| Element | Range | Role |
|---|---|---|
| Cu copper | 3.9–5.0 | the main element: gives the strength |
| Si silicon | 0.50–1.2 | improves the heat-treatment response and forging |
| Mn manganese | 0.40–1.2 | controls the grain structure |
| Fe iron | max 1.0 | |
| Zn zinc | max 0.25 | |
| Ti titanium | max 0.15 | |
| Cr chromium | max 0.10 | |
| Mg magnesium | max 0.05 | |
| Al aluminum | balance |
Common tempers
2025 is supplied mostly as forgings in the T6 temper.
| Temper | Properties | When to choose it |
|---|---|---|
| O | annealed | for machining and forming |
| T4 | naturally aged | lower strength, high ductility |
| T6 | Rm ≈ 400 MPa, Rp0.2 ≈ 310 MPa | artificially aged: the common temper |
Applications
- Propellers and propeller hubs
- Forged aerospace parts
- Forged machine parts
- Existing parts made to older specifications
- General forgings of medium-high strength
Fabrication
Forging
Forges well, which is what it was developed for.
Welding
Fusion welding is not recommended.
Corrosion
Low resistance because of the copper. Protect with coatings and paint.
Compared with similar materials
| Material | Rm / Rp0.2 | Welding | When it is the better choice |
|---|---|---|---|
| 2014-T6 | 483 / 414 MPa | Not recommended | stronger, and the common choice for forgings today · material page |
| 2024-T4 | 470–480 / 325–345 MPa | Not recommended — Hot Cracking | for sheet and fatigue-loaded parts · material page |
| 6061-T6 | 310 / 276 MPa | Good — ER4043 | when corrosion resistance and weldability are needed · material page |
Common mistakes
Ordering 2025 for a new design without checking
It is less available today. For a new design, check 2014.
Welding 2025
Fusion welding is not recommended.
Leaving a part unprotected
The copper lowers corrosion resistance.
Equivalents, standards and supply
| ASTM | 2025 |
|---|---|
| Standards | ASTM B247 |
| Forms | forging only |
| Producers | Alcoa · Constellium · Kaiser |
Learn more
Values are typical and for comparison only. For design, rely on the standard and on the mill certificate. Sources: Aluminum Association (composition), ASM and MatWeb data sheets, and the METAL HUB materials database.
Updated: October 31, 2026