Aluminum 2050-T851
Temper
AA 2050 · UNS A92050
T851 = t8, stress relieved by stretching
Thick plate condition with controlled residual stress for large machined monolithic parts with tight distortion limits.
Values for the T851 condition
Other 2050 tempers and conditions
2050 is listed in 6 conditions; see the grade overview at 2050.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, supplied for severe forming or re-heat-treatment; strength must be restored by solution treating and ageing. | 135 | 250 | 18 | 65 HB | 38 % IACS |
Solution heat treated, ~3–4 % stretched and naturally aged | Choose when plate must be stretch-formed, roll-formed or machined near net shape before ageing to T84. | 305 | 430 | 17 | 112 HB | 24 % IACS |
Solution heat treated, cold worked and naturally aged | Intermediate as-delivered condition for parts that will be formed/machined and then artificially aged to T8. | 320 | 440 | 15 | 115 HB | 24 % IACS |
T851This page T8, stress relieved by stretching | Thick plate condition with controlled residual stress for large machined monolithic parts with tight distortion limits. | 480 | 520 | 8 | 147 HB | 28 % IACS |
T84Default Solution heat treated, stretched and artificially aged | Standard aerospace plate delivery condition: best balance of strength, toughness and corrosion resistance for machined structural parts. | 495 | 530 | 9 | 150 HB | 28 % IACS |
Solution heat treated, heavily cold worked and artificially aged | Highest-strength condition, used for extruded stringers and stiffeners where ductility and toughness may be traded for strength. | 540 | 570 | 7 | 160 HB | 29 % IACS |
What is 2050-T851?
2050-T851 is 2050 in the T851 temper — thick plate condition with controlled residual stress for large machined monolithic parts with tight distortion limits. 2050-T851 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 95% of aluminum grades. Elongation at break is 8% and the elastic modulus is 76.5 GPa (11.1 Msi). 2050-T851 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 560°C (1,040 °F). T84 is the default condition FabDigit quotes; T851 is available on request or by drawing note.
Advantages
- High strength — 480 MPa (69.6 ksi), better than 95% of aluminum grades
- Tough — resists crack growth — 36 MPa·√m (32.8 ksi·√in), better than 93% of aluminum grades
Limitations
- Poor heat conductor — 95 W/m·K (54.9 BTU/hr·ft·°F), worse than 98% of aluminum grades
- Low electrical conductivity — 28 % IACS, worse than 82% of aluminum grades
2050-T851 properties
Typical room-temperature values for 2050-T851; 22 are specific to this condition. Other listed values are 2050 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2050-T851 has a density of 2.7 g/cm³ (0.0975 lb/in³), lighter than 59% of aluminum grades. It melts at 560°C (1,040 °F).
Mechanical11
2050-T851 has a yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 95% of aluminum grades. Elongation at break is 8% and the elastic modulus is 76.5 GPa (11.1 Msi).
Thermal6
2050-T851 is rated for continuous service to 150°C (302 °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 µm/m·K (12.2 µin/in·°F).
Electrical3
2050-T851 conducts electricity at 28 % IACS, worse than 82% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (42/100), worse than 69% of aluminum grades.
Sustainability4
Producing a kilogram of 2050-T851 takes about 215 MJ of energy and emits 13 kg of CO₂ — more than 93% of aluminum grades. Typical recycled content is 8%.
Manufacturability8
2050-T851's machinability is very good (70/100, better than 72% of aluminum grades); weldability poor (30/100); formability poor (20/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2050-T851
Is 2050 easy to machine?
Machines like a hard 2000-series alloy: sharp carbide tools, high speed with flood coolant, symmetric stock removal and stress-relieved (T851) plate to limit distortion in monolithic parts; keep Li-bearing chips dry and segregated.
Can 2050 be welded?
Not recommended for fusion welding (hot cracking, Li oxide/porosity); joined by friction stir welding, laser-beam welding with tailored filler, riveting or bonding.
Can 2050 be formed, bent or molded?
Form in O or T34 before ageing — cold formability in T84 is limited and the alloy shows marked anisotropy; hot forming and creep-age forming of panels are practiced.
What surface finishes work on 2050?
Alkaline etch/deoxidize then chromic or thin-film sulfuric anodize plus primer for aerospace protection; avoid decorative anodizing (dark, streaky films) and insulate joints to CFRP or steel.
2050 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 |
|---|---|---|
| Si | ≤ 0.08 | 0.03 |
| Fe | ≤ 0.1 | 0.05 |
| Cu | 3.2 – 3.9 | 3.5 |
| Mn | 0.2 – 0.5 | 0.35 |
| Mg | 0.2 – 0.6 | 0.4 |
| Lidensity-reducing, stiffness-increasing addition | 0.7 – 1.3 | 1 |
| Agpromotes T1 precipitation | 0.2 – 0.7 | 0.4 |
| Zrgrain-structure control | 0.06 – 0.14 | 0.1 |
| Ti | ≤ 0.1 | 0.03 |
| Zn | ≤ 0.25 | 0.05 |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
2050-T851 — frequently asked
What is 2050-T851 used for?
2050-T851 is typically used for aircraft fuselage plate, wing ribs and spars. In short: lower-density 2024 upgrade; stiff Al-Cu-Li plate; better corrosion than 2024.
What is the yield strength of 2050-T851?
2050-T851 has a typical yield strength of 480 MPa (69.6 ksi) and a tensile strength of 520 MPa (75.4 ksi) — stronger than 95% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 2050-T851 easy to machine?
Yes — machinability is rated very good (70/100, better than 72% of aluminum grades). Machines like a hard 2000-series alloy: sharp carbide tools, high speed with flood coolant, symmetric stock removal and stress-relieved (T851) plate to limit distortion in monolithic parts; keep Li-bearing chips dry and segregated.
Can 2050-T851 be welded?
Not readily — weldability is rated poor (30/100). Not recommended for fusion welding (hot cracking, Li oxide/porosity); joined by friction stir welding, laser-beam welding with tailored filler, riveting or bonding.
What surface finishes work on 2050-T851?
Alkaline etch/deoxidize then chromic or thin-film sulfuric anodize plus primer for aerospace protection; avoid decorative anodizing (dark, streaky films) and insulate joints to CFRP or steel.
Can 2050-T851 be formed, bent or molded?
Form in O or T34 before ageing — cold formability in T84 is limited and the alloy shows marked anisotropy; hot forming and creep-age forming of panels are practiced.
What is the maximum service temperature of 2050-T851?
2050-T851 is rated for continuous use to about 150°C (302 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 2050-T84 and 2050-O?
T84 is the default condition — standard aerospace plate delivery condition: best balance of strength, toughness and corrosion resistance for machined structural parts. O: softest condition, supplied for severe forming or re-heat-treatment; strength must be restored by solution treating and ageing. Yield strength is 495 MPa in T84 versus 135 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets), alloy 2050 — The Aluminum Association (2018)
- Airware 2050 plate technical data — Constellium (2020)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys — ASM International (1990)
- Aluminum-Lithium Alloys: Processing, Properties and Applications — Elsevier/Butterworth-Heinemann (2014)
- MMPDS-style typical property compilations for Al-Li plate — Battelle/FAA (2021)
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.