Aluminum 2524-T39
Temper
AA 2524 · UNS A92524
T39 = solution heat treated, extra cold worked, naturally aged
Higher-yield stretched/cold-rolled variant for lower-wing or skin applications where strength governs over maximum toughness.
Values for the T39 condition
Other 2524 tempers and conditions
2524 is listed in 7 conditions; see the grade overview at 2524.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or intermediate processing; must be re-solution treated and aged to reach service properties. | 78 | 185 | 20 | 47 HB | 50 % IACS |
Solution heat treated and naturally aged | Use where the cold-work step of T3 is not applied, e.g. after forming and re-solution treatment. | 295 | 435 | 22 | 112 HB | 30 % IACS |
Alclad 2524-T3 | Cladding-protected fuselage skin sheet: much better corrosion resistance, slightly lower net strength because the clad layer carries little load. | 310 | 435 | 20 | 115 HB | 32 % IACS |
T3, stress relieved by stretching | Plate/heavy-sheet version with low residual stress for machined damage-tolerant structure. | 325 | 455 | 20 | 118 HB | 30 % IACS |
T3Default Solution heat treated, cold worked and naturally aged | Standard fuselage-skin sheet condition: best balance of static strength, fracture toughness and fatigue-crack-growth resistance. | 330 | 455 | 21 | 120 HB | 30 % IACS |
T39This page Solution heat treated, extra cold worked, naturally aged | Higher-yield stretched/cold-rolled variant for lower-wing or skin applications where strength governs over maximum toughness. | 395 | 480 | 13 | 130 HB | 31 % IACS |
Solution heat treated, cold worked and artificially aged | Artificially aged high-strength condition with improved thermal stability and intergranular-corrosion behaviour; toughness lower than T3. | 460 | 500 | 8 | 140 HB | 38 % IACS |
What is 2524-T39?
2524-T39 is 2524 in the T39 temper — higher-yield stretched/cold-rolled variant for lower-wing or skin applications where strength governs over maximum toughness. 2524-T39 has a yield strength of 395 MPa (57.3 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 88% of aluminum grades. Elongation at break is 13% and the elastic modulus is 72.4 GPa (10.5 Msi). 2524-T39 has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 502°C (936 °F). T3 is the default condition FabDigit quotes; T39 is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 36 MPa·√m (32.8 ksi·√in), better than 93% of aluminum grades
- High strength — 395 MPa (57.3 ksi), better than 88% of aluminum grades
- Easy to machine — 74/100, better than 85% of aluminum grades
- Ductile — tolerates forming and impact — 13%, better than 79% of aluminum grades
Limitations
- Needs corrosion protection — 32/100, worse than 94% of aluminum grades
- Difficult to weld — 18/100, worse than 94% of aluminum grades
- Limited service temperature — 120°C (248 °F), worse than 79% of aluminum grades
2524-T39 properties
Typical room-temperature values for 2524-T39; 22 are specific to this condition. Other listed values are 2524 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2524-T39 has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 502°C (936 °F).
Mechanical14
2524-T39 has a yield strength of 395 MPa (57.3 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 88% of aluminum grades. Elongation at break is 13% and the elastic modulus is 72.4 GPa (10.5 Msi).
Thermal6
2524-T39 is rated for continuous service to 120°C (248 °F). It conducts heat at 123 W/m·K (71.1 BTU/hr·ft·°F), worse than 74% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
2524-T39 conducts electricity at 31 % IACS, worse than 68% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 2524-T39 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 8%.
Manufacturability7
2524-T39's machinability is very good (74/100, better than 85% of aluminum grades); weldability poor (18/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2524-T39
Is 2524 easy to machine?
Machines very freely in T3/T351 with sharp polished carbide tools, high speed and flood coolant; produces long chips, so use high-rake geometry and chip breakers.
Can 2524 be welded?
Not suitable for arc fusion welding (hot cracking, loss of temper); join by riveting, bonding or friction stir welding with post-weld property allowance.
Can 2524 be formed, bent or molded?
Form T3 sheet with generous bend radii (≈3–4 t) or use freshly solution-treated/refrigerated 'W' material; brake-form across the rolling direction where possible.
What surface finishes work on 2524?
Standard aerospace route is chromic or thin-film sulfuric anodize (or conversion coating) followed by epoxy primer/topcoat; bare surfaces need cladding or coating for chloride exposure.
2524 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Cuprincipal strengthening element | 4 – 4.5 | 4.25 |
| Mg | 1.2 – 1.6 | 1.4 |
| Mndispersoid former, grain control | 0.45 – 0.7 | 0.6 |
| Sitightly restricted for toughness | ≤ 0.06 | 0.03 |
| Fetightly restricted; limits coarse constituent particles | ≤ 0.12 | 0.06 |
| Cr | ≤ 0.05 | — |
| Zn | ≤ 0.15 | — |
| Ti | ≤ 0.1 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
2524-T39 — frequently asked
What is 2524-T39 used for?
2524-T39 is typically used for fuselage skin sheet, pressure cabin skin panels, damage-tolerant aerospace sheet structure, formed stringers and frames from sheet, access panels and doors and repair doublers and skin patches. In short: damage-tolerant 2024 upgrade; high-elongation 2000-series sheet; available as Alclad sheet.
What is the yield strength of 2524-T39?
2524-T39 has a typical yield strength of 395 MPa (57.3 ksi) and a tensile strength of 480 MPa (69.6 ksi) — stronger than 88% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is 2524-T39 easy to machine?
Yes — machinability is rated very good (74/100, better than 85% of aluminum grades). Machines very freely in T3/T351 with sharp polished carbide tools, high speed and flood coolant; produces long chips, so use high-rake geometry and chip breakers.
Can 2524-T39 be welded?
Not readily — weldability is rated poor (18/100). Not suitable for arc fusion welding (hot cracking, loss of temper); join by riveting, bonding or friction stir welding with post-weld property allowance.
What surface finishes work on 2524-T39?
Standard aerospace route is chromic or thin-film sulfuric anodize (or conversion coating) followed by epoxy primer/topcoat; bare surfaces need cladding or coating for chloride exposure.
Can 2524-T39 be formed, bent or molded?
Form T3 sheet with generous bend radii (≈3–4 t) or use freshly solution-treated/refrigerated 'W' material; brake-form across the rolling direction where possible.
What is the maximum service temperature of 2524-T39?
2524-T39 is rated for continuous use to about 120°C (248 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 2524-T3 and 2524-O?
T3 is the default condition — standard fuselage-skin sheet condition: best balance of static strength, fracture toughness and fatigue-crack-growth resistance. O: softest condition for severe forming or intermediate processing; must be re-solution treated and aged to reach service properties. Yield strength is 330 MPa in T3 versus 78 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- AMS 4296 — Aluminum Alloy, Alclad Sheet 2524-T3 — SAE International (2019)
- MMPDS — Metallic Materials Properties Development and Standardization — FAA/Battelle (2023)
- ASM Handbook Vol.2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- Alcoa/Arconic 2524 damage-tolerant fuselage sheet product information — Alcoa (2015)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.