Aluminum 2056-T4
Temper
AA 2056 · UNS A92056
T4 = solution heat treated and naturally aged
Used when parts are formed after solution treatment; slightly lower yield than T3 but better forming ductility.
Values for the T4 condition
Other 2056 tempers and conditions
2056 is listed in 7 conditions; see the grade overview at 2056.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Soft delivery/intermediate condition for severe forming; must be re-solution-treated and aged for service properties. | 115 | 230 | 22 | 60 HB | 40 % IACS |
T4This page Solution heat treated and naturally aged | Used when parts are formed after solution treatment; slightly lower yield than T3 but better forming ductility. | 300 | 440 | 20 | 118 HB | 30 % IACS |
T3, stress relieved by stretching | Stress-relieved plate/thick-sheet version of T3 for machined parts where residual-stress distortion must be minimised. | 320 | 450 | 15 | 123 HB | 30 % IACS |
T3Default Solution heat treated, cold worked and naturally aged | Standard damage-tolerant fuselage-skin condition: 2024-T3-class strength with lower density and slower fatigue crack growth. | 325 | 455 | 17 | 125 HB | 30 % IACS |
Solution heat treated, cold worked and artificially aged | Peak/near-peak aged condition for higher yield strength and stiffness-critical skins; some loss of toughness and ductility versus T3. | 440 | 490 | 10 | 148 HB | 33 % IACS |
Solution heat treated, stretched and artificially aged to near-peak… | Commercial high-strength sheet temper for lower fuselage/stringer applications where static strength drives the design. | 450 | 500 | 10 | 150 HB | 33 % IACS |
T8, stress relieved by stretching | Stress-relieved aged plate for machined structural fittings and thick skins needing dimensional stability. | 450 | 495 | 8 | 150 HB | 33 % IACS |
What is 2056-T4?
2056-T4 is 2056 in the T4 temper — used when parts are formed after solution treatment; slightly lower yield than T3 but better forming ductility. 2056-T4 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 77% of aluminum grades. Elongation at break is 20% and the elastic modulus is 77 GPa (11.2 Msi). 2056-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 545°C (1,013 °F). T3 is the default condition FabDigit quotes; T4 is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 40 MPa·√m (36.4 ksi·√in), better than 98% of aluminum grades
- Ductile — tolerates forming and impact — 20%, better than 89% of aluminum grades
- Forms and bends easily — 68/100, better than 81% of aluminum grades
- High strength — 300 MPa (43.5 ksi), better than 77% of aluminum grades
Limitations
- Poor heat conductor — 95 W/m·K (54.9 BTU/hr·ft·°F), worse than 98% of aluminum grades
- Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
- Difficult to weld — 25/100, worse than 76% of aluminum grades
- Needs corrosion protection — 40/100, worse than 75% of aluminum grades
2056-T4 properties
Typical room-temperature values for 2056-T4; 22 are specific to this condition. Other listed values are 2056 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2056-T4 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 545°C (1,013 °F).
Mechanical12
2056-T4 has a yield strength of 300 MPa (43.5 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 77% of aluminum grades. Elongation at break is 20% and the elastic modulus is 77 GPa (11.2 Msi).
Thermal6
2056-T4 is rated for continuous service to 100°C (212 °F). It conducts heat at 95 W/m·K (54.9 BTU/hr·ft·°F), worse than 98% of aluminum grades. Thermal expansion is 22.6 µm/m·K (12.6 µin/in·°F).
Electrical3
2056-T4 conducts electricity at 30 % IACS, worse than 73% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (40/100), worse than 75% of aluminum grades.
Sustainability4
Producing a kilogram of 2056-T4 takes about 225 MJ of energy and emits 13.5 kg of CO₂ — more than 96% of aluminum grades. Typical recycled content is 5%.
Manufacturability7
2056-T4's machinability is good (58/100, worse than 54% of aluminum grades); weldability poor (25/100); formability good (68/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2056-T4
Is 2056 easy to machine?
Machines like 2024 but Li-bearing chips are abrasive and reactive — use sharp carbide/PCD tools, high speed, generous coolant, and collect chips separately (do not mix with water-based sludge storage).
Can 2056 be welded?
Not suitable for conventional fusion welding (porosity, Li oxide, hot cracking); joined by riveting or friction stir welding, which is the intended process for Airware-type structures.
Can 2056 be formed, bent or molded?
Formed in T3/T4 or O condition; strong crystallographic texture makes properties directional, so plan bend lines relative to rolling direction and expect higher springback than 2024.
What surface finishes work on 2056?
Standard aerospace route: chromic or tartaric-sulfuric anodise plus chromate-free primer; clad or coated surfaces recommended for chloride exposure, decorative bright anodising is not achievable.
2056 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 |
|---|---|---|
| Cuapproximate AA registration range | 3.2 – 4.2 | 3.6 |
| Limain density-reducing / modulus-raising addition | 0.6 – 1.3 | 1 |
| Mg | 0.2 – 0.6 | 0.35 |
| Agaging accelerator in some registrations | 0.1 – 0.6 | 0.3 |
| Mn | 0.1 – 0.8 | 0.3 |
| Zn | 0 – 0.8 | 0.3 |
| Zrgrain-structure control | 0.04 – 0.18 | 0.1 |
| Ti | ≤ 0.1 | — |
| Fe | ≤ 0.15 | — |
| Si | ≤ 0.1 | — |
| Others (each)0.15 total | ≤ 0.05 | — |
| Al | balance | — |
2056-T4 — frequently asked
What is 2056-T4 used for?
2056-T4 is typically used for fuselage skin sheet, damage-tolerant aerospace panels, pressurised cabin shell sections, friction-stir-welded skin assemblies, riveted airframe secondary structure and weight-reduction skin replacements. In short: damage-tolerant Al-Li sheet; lower density than 2024; friction-stir weld intended.
What is the yield strength of 2056-T4?
2056-T4 has a typical yield strength of 300 MPa (43.5 ksi) and a tensile strength of 440 MPa (63.8 ksi) — stronger than 77% of aluminum grades. Strength varies by condition: see the 7 listed tempers.
Is 2056-T4 easy to machine?
Reasonably — machinability is rated good (58/100, worse than 54% of aluminum grades). Machines like 2024 but Li-bearing chips are abrasive and reactive — use sharp carbide/PCD tools, high speed, generous coolant, and collect chips separately (do not mix with water-based sludge storage).
Can 2056-T4 be welded?
Not readily — weldability is rated poor (25/100). Not suitable for conventional fusion welding (porosity, Li oxide, hot cracking); joined by riveting or friction stir welding, which is the intended process for Airware-type structures.
What surface finishes work on 2056-T4?
Standard aerospace route: chromic or tartaric-sulfuric anodise plus chromate-free primer; clad or coated surfaces recommended for chloride exposure, decorative bright anodising is not achievable.
Can 2056-T4 be formed, bent or molded?
Formed in T3/T4 or O condition; strong crystallographic texture makes properties directional, so plan bend lines relative to rolling direction and expect higher springback than 2024.
What is the maximum service temperature of 2056-T4?
2056-T4 is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 2056-T3 and 2056-O?
T3 is the default condition — standard damage-tolerant fuselage-skin condition: 2024-T3-class strength with lower density and slower fatigue crack growth. O: soft delivery/intermediate condition for severe forming; must be re-solution-treated and aged for service properties. Yield strength is 325 MPa in T3 versus 115 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- Airware Al-Li alloy product literature (2050/2056/2198 family) — Constellium (2021)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
- MMPDS-style typical property practice for damage-tolerant Al sheet — Battelle/FAA (2023)
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.