Aluminum 2048-T851
Temper · default condition
AA 2048 · UNS A92048
T851 = t8, stress relieved by stretching
Standard aerospace plate condition: peak-strength artificial ageing with stretch stress relief, giving high strength plus good fracture toughness and low residual stress for machined structure.
Values for the T851 condition
Other 2048 tempers and conditions
2048 is listed in 5 conditions; see the grade overview at 2048.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, used only for severe forming or intermediate processing before re-solution treatment. | 90 | 200 | 18 | 48 HB | 50 % IACS |
T3, stress relieved by stretching | Naturally aged plate with the best ductility and toughness of the heat-treated conditions; usually an intermediate step before artificial ageing to T851. | 275 | 425 | 17 | 110 HB | 30 % IACS |
T73, stress relieved by stretching | Overaged option when maximum resistance to exfoliation/stress-corrosion is needed in thick sections, at some loss of strength; only occasionally supplied for 2048. | 360 | 420 | 10 | 115 HB | 42 % IACS |
Solution treated, cold worked, artificially aged | Thin-gauge equivalent of T851 where stretch stress relief is not applied; used for sheet skins and detail parts. | 415 | 450 | 6 | 128 HB | 38 % IACS |
T851DefaultThis page T8, stress relieved by stretching | Standard aerospace plate condition: peak-strength artificial ageing with stretch stress relief, giving high strength plus good fracture toughness and low residual stress for machined structure. | 416 | 457 | 9 | 125 HB | 38 % IACS |
What is 2048-T851?
2048-T851 is 2048 in the T851 temper — standard aerospace plate condition: peak-strength artificial ageing with stretch stress relief, giving high strength plus good fracture toughness and low residual stress for machined structure. 2048-T851 has a yield strength of 416 MPa (60.3 ksi) and a tensile strength of 457 MPa (66.3 ksi) — stronger than 89% of aluminum grades. Elongation at break is 9% and the elastic modulus is 70.3 GPa (10.2 Msi). 2048-T851 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 507°C (945 °F).
Advantages
- Tough — resists crack growth — 37 MPa·√m (33.7 ksi·√in), better than 94% of aluminum grades
- High strength — 416 MPa (60.3 ksi), better than 89% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Difficult to weld — 20/100, worse than 89% of aluminum grades
- Needs corrosion protection — 35/100, worse than 85% of aluminum grades
2048-T851 properties
Typical room-temperature values for 2048-T851; 14 are specific to this condition. Other listed values are 2048 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2048-T851 has a density of 2.75 g/cm³ (0.0994 lb/in³), heavier than 67% of aluminum grades. It melts at 507°C (945 °F).
Mechanical12
2048-T851 has a yield strength of 416 MPa (60.3 ksi) and a tensile strength of 457 MPa (66.3 ksi) — stronger than 89% of aluminum grades. Elongation at break is 9% and the elastic modulus is 70.3 GPa (10.2 Msi).
Thermal6
2048-T851 is rated for continuous service to 150°C (302 °F). It conducts heat at 151 W/m·K (87.2 BTU/hr·ft·°F), better than 63% of aluminum grades. Thermal expansion is 23.2 µm/m·K (12.9 µin/in·°F).
Electrical3
2048-T851 conducts electricity at 38 % IACS, better than 61% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (35/100), worse than 85% of aluminum grades.
Sustainability4
Producing a kilogram of 2048-T851 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 10%.
Manufacturability7
2048-T851's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (20/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2048-T851
Is 2048 easy to machine?
Machines very well in T851 with sharp carbide tools, high speed and flood coolant; chips break cleanly, but leave stress-symmetric stock removal on thick plate to limit distortion.
Can 2048 be welded?
Not recommended for fusion welding (hot-cracking and loss of T8 properties); join by riveting, bolting, adhesive bonding or friction stir welding with qualified procedures.
Can 2048 be formed, bent or molded?
Form in O or freshly quenched W temper; T851 plate tolerates only mild bending with generous radii, so most parts are machined from plate.
What surface finishes work on 2048?
Chromic or sulfuric anodize plus primer, or Alclad/ion-vapour-deposited Al coating, is normal; bare surfaces pit in chloride service and colour anodizing is dull due to copper.
2048 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 |
|---|---|---|
| Silow-Si for toughness | ≤ 0.15 | 0.06 |
| Felow-Fe for toughness | ≤ 0.2 | 0.1 |
| Cu | 2.8 – 3.8 | 3.3 |
| Mn | 0.2 – 0.6 | 0.4 |
| Mg | 1.2 – 1.8 | 1.5 |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.1 | — |
| Others (each) | ≤ 0.05 | — |
| Others (total) | ≤ 0.15 | — |
| Al | balance | — |
2048-T851 — frequently asked
What is 2048-T851 used for?
2048-T851 is typically used for aircraft structural plate, machined spacers and fittings, bulkheads and frames, wing ribs and shear webs, landing-gear support brackets and access-door and panel backing structure. In short: tough 2000-series airframe plate; good-machining structural alloy; machined, not formed.
What is the yield strength of 2048-T851?
2048-T851 has a typical yield strength of 416 MPa (60.3 ksi) and a tensile strength of 457 MPa (66.3 ksi) — stronger than 89% of aluminum grades. Strength varies by condition: see the 5 listed tempers.
Is 2048-T851 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines very well in T851 with sharp carbide tools, high speed and flood coolant; chips break cleanly, but leave stress-symmetric stock removal on thick plate to limit distortion.
Can 2048-T851 be welded?
Not readily — weldability is rated poor (20/100). Not recommended for fusion welding (hot-cracking and loss of T8 properties); join by riveting, bolting, adhesive bonding or friction stir welding with qualified procedures.
What surface finishes work on 2048-T851?
Chromic or sulfuric anodize plus primer, or Alclad/ion-vapour-deposited Al coating, is normal; bare surfaces pit in chloride service and colour anodizing is dull due to copper.
Can 2048-T851 be formed, bent or molded?
Form in O or freshly quenched W temper; T851 plate tolerates only mild bending with generous radii, so most parts are machined from plate.
What is the maximum service temperature of 2048-T851?
2048-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 2048-T851 and 2048-O?
T851 is the default condition — standard aerospace plate condition: peak-strength artificial ageing with stretch stress relief, giving high strength plus good fracture toughness and low residual stress for machined structure. O: softest condition, used only for severe forming or intermediate processing before re-solution treatment. Yield strength is 416 MPa in T851 versus 90 MPa in O.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- ASM Handbook Vol. 2: Properties and Selection — Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- MMPDS-17 Metallic Materials Properties Development and Standardization — Battelle/FAA (2022)
- ASTM B209 / AMS-QQ-A-250 aluminium plate specifications — ASTM / SAE (2021)
- ASM Handbook Vol. 13B: Corrosion — Materials — ASM International (2005)
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.