Aluminum 2195-T851
Temper
AA 2195 · UNS A92195
T851 = t8, stress relieved by stretching
Stretched plate temper for thick machined structure where residual-stress-driven distortion must be minimised.
Values for the T851 condition
Other 2195 tempers and conditions
2195 is listed in 10 conditions; see the grade overview at 2195.
Compare all 10 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition, used for severe forming or intermediate processing before re-solution treating. | 150 | 270 | 18 | 70 HB | 34 % IACS |
Solution heat treated, cold worked and naturally aged | Intermediate forming temper: enough ductility to stretch-form or roll panels before the final artificial age to T8. | 300 | 430 | 15 | 115 HB | 25 % IACS |
Solution heat treated and artificially aged | Used for forgings/parts that cannot be stretched; lower strength than T8 because T1 precipitation is not dislocation-assisted. | 470 | 530 | 8 | 148 HB | 30 % IACS |
Solution heat treated, cold worked, artificially aged | Aerospace plate temper trading a little strength for better ductility, short-transverse toughness and forming after ageing. | 525 | 570 | 10 | 155 HB | 30 % IACS |
Solution heat treated, ~1 % cold worked, artificially aged | Low cold-work T8 variant for parts with limited stretch capability; slightly lower strength than T87. | 540 | 580 | 8 | 157 HB | 29 % IACS |
T8Default Solution heat treated, cold worked and artificially aged | Standard high-strength delivery condition for 2195 plate and extrusions; the temper used on cryogenic tank structure. | 550 | 590 | 9 | 160 HB | 29 % IACS |
T851This page T8, stress relieved by stretching | Stretched plate temper for thick machined structure where residual-stress-driven distortion must be minimised. | 550 | 590 | 9 | 160 HB | 29 % IACS |
Solution heat treated, cold worked ~2 %, artificially aged | AMS-registered plate temper for cryogenic tank barrel and dome gores; best balance of strength and cryogenic toughness. | 560 | 600 | 8 | 163 HB | 29 % IACS |
T8 with 7 % cold work | Peak-strength temper for strength-critical panels; lowest ductility and toughness of the 2195 T8 family. | 580 | 615 | 7 | 170 HB | 29 % IACS |
Solution heat treated, cold worked ~3 %, artificially aged | Highest-strength extrusion temper for stringers and ring frames where longitudinal strength dominates. | 580 | 615 | 6 | 168 HB | 28 % IACS |
What is 2195-T851?
2195-T851 is 2195 in the T851 temper — stretched plate temper for thick machined structure where residual-stress-driven distortion must be minimised. 2195-T851 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 97% of aluminum grades. Elongation at break is 9% and the elastic modulus is 76 GPa (11 Msi). 2195-T851 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 570°C (1,058 °F). T8 is the default condition FabDigit quotes; T851 is available on request or by drawing note.
Advantages
- High strength — 550 MPa (79.8 ksi), better than 97% of aluminum grades
- Tough — resists crack growth — 33 MPa·√m (30 ksi·√in), better than 87% of aluminum grades
Limitations
- Poor heat conductor — 115 W/m·K (66.4 BTU/hr·ft·°F), worse than 85% of aluminum grades
- Needs corrosion protection — 38/100, worse than 79% of aluminum grades
- Low electrical conductivity — 29 % IACS, worse than 78% of aluminum grades
2195-T851 properties
Typical room-temperature values for 2195-T851; 21 are specific to this condition. Other listed values are 2195 reference data and may not represent this condition. Bars are the position among aluminum grades.
Physical3
2195-T851 has a density of 2.71 g/cm³ (0.0979 lb/in³), heavier than 51% of aluminum grades. It melts at 570°C (1,058 °F).
Mechanical14
2195-T851 has a yield strength of 550 MPa (79.8 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 97% of aluminum grades. Elongation at break is 9% and the elastic modulus is 76 GPa (11 Msi).
Thermal6
2195-T851 is rated for continuous service to 150°C (302 °F). It conducts heat at 115 W/m·K (66.4 BTU/hr·ft·°F), worse than 85% of aluminum grades. Thermal expansion is 22 µm/m·K (12.2 µin/in·°F).
Electrical3
2195-T851 conducts electricity at 29 % IACS, worse than 78% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is fair (38/100), worse than 79% of aluminum grades.
Sustainability4
Producing a kilogram of 2195-T851 takes about 215 MJ of energy and emits 13.5 kg of CO₂ — more than 93% of aluminum grades. Typical recycled content is 5%.
Manufacturability8
2195-T851's machinability is good (62/100, better than 55% of aluminum grades); weldability good (62/100); formability poor (28/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 2195-T851
Is 2195 easy to machine?
Machines like a hard 2000-series-T8: sharp uncoated carbide, high speed, generous flood coolant; Li-bearing fines are reactive, so collect chips wet and avoid dry grinding.
Can 2195 be welded?
Designed for fusion welding (VPPA/GTAW with 4043/2319-type filler) and is an excellent friction-stir-welding alloy; keep heat input low and expect a softened, re-agable HAZ.
Can 2195 be formed, bent or molded?
Form in O or T3 then age to T8; T8 tempers are stiff and anisotropic with limited bend radii, so use warm forming or creep-age forming for curved panels.
What surface finishes work on 2195?
Chromic/sulfuric anodize or chromate/Cr-free conversion coat plus epoxy primer; bare surfaces pit in chloride service and Cu/Li phases make dyed anodize colours inconsistent.
2195 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 |
|---|---|---|
| Cu | 3.7 – 4.3 | 4 |
| Liprimary density reducer | 0.8 – 1.2 | 1 |
| Mg | 0.25 – 0.8 | 0.4 |
| Agpromotes T1 nucleation | 0.25 – 0.6 | 0.4 |
| Zrgrain-structure control | 0.08 – 0.16 | 0.12 |
| Mn | ≤ 0.25 | — |
| Fe | ≤ 0.15 | — |
| Si | ≤ 0.12 | — |
| Zn | ≤ 0.25 | — |
| Ti | ≤ 0.1 | — |
| Others (each)total 0.15 max | ≤ 0.05 | — |
| Al | balance | — |
2195-T851 — frequently asked
What is 2195-T851 used for?
2195-T851 is typically used for cryogenic fuel tanks, aerospace structures, launch vehicle tank barrels and domes, friction-stir-welded tank panels, machined airframe frames and ribs and weight-critical spacecraft brackets. In short: aluminum-lithium; low density; cryogenic-grade.
What is the yield strength of 2195-T851?
2195-T851 has a typical yield strength of 550 MPa (79.8 ksi) and a tensile strength of 590 MPa (85.6 ksi) — stronger than 97% of aluminum grades. Strength varies by condition: see the 10 listed tempers.
Is 2195-T851 easy to machine?
Reasonably — machinability is rated good (62/100, better than 55% of aluminum grades). Machines like a hard 2000-series-T8: sharp uncoated carbide, high speed, generous flood coolant; Li-bearing fines are reactive, so collect chips wet and avoid dry grinding.
Can 2195-T851 be welded?
Yes — weldability is rated good (62/100). Designed for fusion welding (VPPA/GTAW with 4043/2319-type filler) and is an excellent friction-stir-welding alloy; keep heat input low and expect a softened, re-agable HAZ.
What surface finishes work on 2195-T851?
Chromic/sulfuric anodize or chromate/Cr-free conversion coat plus epoxy primer; bare surfaces pit in chloride service and Cu/Li phases make dyed anodize colours inconsistent.
Can 2195-T851 be formed, bent or molded?
Form in O or T3 then age to T8; T8 tempers are stiff and anisotropic with limited bend radii, so use warm forming or creep-age forming for curved panels.
What is the maximum service temperature of 2195-T851?
2195-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 2195-T8 and 2195-O?
T8 is the default condition — standard high-strength delivery condition for 2195 plate and extrusions; the temper used on cryogenic tank structure. O: softest condition, used for severe forming or intermediate processing before re-solution treating. Yield strength is 550 MPa in T8 versus 150 MPa in O.
Can FabDigit make parts in 2195-T851?
Yes — 2195-T851 is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
- AMS 4472 — Aluminum Alloy 2195 Plate — SAE International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Al-Li alloys) — ASM International (1990)
- Aluminum-Lithium Alloys: Processing, Properties and Applications — Elsevier/Butterworth-Heinemann (2014)
- Al-Li alloy product data (2195/2050/2198) — Constellium / Arconic (2021)
- Super Lightweight External Tank 2195 material characterization reports — NASA / Lockheed Martin (1998)
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.