Aluminum 2219 · temper
Aluminum 2219-T31
Properties of the T31 condition, compared with the other 2219 tempers.
Intermediate condition for forming/welding of sheet and plate before final T81 artificial aging.
What is 2219-T31?
2219-T31 is 2219 in the T31 temper — intermediate condition for forming/welding of sheet and plate before final T81 artificial aging. 2219-T31 has a yield strength of 248 MPa (36 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 64% of aluminum grades. Elongation at break is 17% and the elastic modulus is 73.8 GPa (10.7 Msi). 2219-T31 has a density of 2.84 g/cm³ (0.103 lb/in³), heavier than 93% of aluminum grades. It melts at 543°C (1,009 °F). T87 is the default condition FabDigit quotes; T31 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 service temperature — 200°C (392 °F), better than 90% of aluminum grades
- Ductile — tolerates forming and impact — 17%, better than 85% of aluminum grades
- Readily welded — 85/100, better than 79% of aluminum grades
Limitations
- Needs corrosion protection — 25/100, worse than 100% of aluminum grades
- Poor heat conductor — 112 W/m·K (64.7 BTU/hr·ft·°F), worse than 87% of aluminum grades
- Low electrical conductivity — 28 % IACS, worse than 82% of aluminum grades
2219-T31 properties
Typical room-temperature values for 2219-T31 — 12 properties are specific to this condition; the rest are grade-level values shared by every 2219 temper. Each bar shows where the value sits among the aluminum grades in FabDigit's library — further right is higher.
Physical3
2219-T31 has a density of 2.84 g/cm³ (0.103 lb/in³), heavier than 93% of aluminum grades. It melts at 543°C (1,009 °F).
Mechanical12
2219-T31 has a yield strength of 248 MPa (36 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 64% of aluminum grades. Elongation at break is 17% and the elastic modulus is 73.8 GPa (10.7 Msi).
Thermal6
2219-T31 is rated for continuous service to 200°C (392 °F). It conducts heat at 112 W/m·K (64.7 BTU/hr·ft·°F), worse than 87% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).
Electrical3
2219-T31 conducts electricity at 28 % IACS, worse than 82% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (25/100), worse than 100% of aluminum grades.
Sustainability4
Producing a kilogram of 2219-T31 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 75% of aluminum grades. Typical recycled content is 5%.
Manufacturability8
2219-T31's machinability is good (60/100, better than 50% of aluminum grades); weldability excellent (85/100); formability fair (45/100).
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other 2219 tempers and conditions
2219 is also supplied in 12 other conditions. The full side-by-side table is on the 2219 overview.
- T87DefaultThe classic launch-vehicle cryogenic tank plate temper: highest 2219 strength with good weld and cryogenic performance.393 MPa yield · 130 HB
- T81Final aged temper of T31 sheet/plate: high strength with better SCC resistance than naturally aged tempers.352 MPa yield · 134 HB
- T8Peak-aged 2219 after cold work — highest usable strength with retained cryogenic toughness and weldability, the standard aerospace tankage condition.350 MPa yield · 130 HB
- T851Low-residual-stress thick plate and rolled bar temper for machined structural fittings.350 MPa yield · 132 HB
- T852Forging temper (AMS 4144) with low residual stress and good short-transverse properties for machined cryogenic hardware.345 MPa yield · 128 HB
- T37Heavily stretched pre-temper used as the starting stock for T87 tank plate; higher strength than T31 with lower ductility.315 MPa yield · 110 HB
- T62Pick when parts are formed or welded soft and then given a full user solution + aging cycle; slightly lower strength than T81/T87.290 MPa yield · 115 HB
- T6Standard peak-aged temper for 2219 die forgings, hand forgings and extrusions (AMS 4143).290 MPa yield · 115 HB
- T3Solution-treated, cold-worked and naturally aged 2219 — moderate strength with good ductility and formability, the usual pre-weld/pre-age condition for sheet and plate.250 MPa yield · 100 HB
- T31Intermediate condition for forming/welding of sheet and plate before final T81 artificial aging.248 MPa yield · 100 HB
- OSoftest, most formable condition for deep forming or before re-solution treatment; annealed at ~415 °C with slow cool.76 MPa yield · 45 HB
Working with 2219-T31
Is 2219 easy to machine?
Machines well in T8x tempers with sharp carbide tools, high speed and flood coolant; gummy and prone to built-up edge in O/T42.
Can 2219 be welded?
Best weldable 2xxx alloy — GTAW/GMAW/EBW/FSW with 2319 filler; welds are quench-sensitive, expect ~60–70 % of parent strength unless post-weld solution + age is possible.
Can 2219 be formed, bent or molded?
Form in O or T31/T42; T87 plate has low cold formability and should be brake-formed with generous radii or hot-formed 150–200 °C.
What surface finishes work on 2219?
Use chromic or thin sulfuric anodize plus primer for corrosion protection (Cu content darkens film); alkaline cleaning must be short to avoid intergranular attack; not suitable for bright decorative anodizing.
2219 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 |
|---|---|---|
| Cumain strengthening addition | 5.8 – 6.8 | 6.3 |
| Mn | 0.2 – 0.4 | 0.3 |
| Si | ≤ 0.2 | — |
| Fe | ≤ 0.3 | — |
| Mg | ≤ 0.02 | — |
| Zn | ≤ 0.1 | — |
| Tigrain refiner | 0.02 – 0.1 | 0.06 |
| Velevated-temperature stability | 0.05 – 0.15 | 0.1 |
| Zrgrain-structure control, weld crack resistance | 0.1 – 0.25 | 0.18 |
| Others (each)each | ≤ 0.05 | — |
| Others (total)total | ≤ 0.15 | — |
| Al | balance | — |
2219-T31 — frequently asked
What is 2219-T31 used for?
2219-T31 is typically used for cryogenic propellant tanks, missile and launch-vehicle structures, welded cryogenic pressure vessels, supersonic airframe structures, machined aerospace forgings and elevated-temperature structural fittings. In short: weldable + cryogenic; aerospace tank.
What is the yield strength of 2219-T31?
2219-T31 has a typical yield strength of 248 MPa (36 ksi) and a tensile strength of 360 MPa (52.2 ksi) — stronger than 64% of aluminum grades. Strength varies by condition: see the 13 listed tempers.
Is 2219-T31 easy to machine?
Reasonably — machinability is rated good (60/100, better than 50% of aluminum grades). Machines well in T8x tempers with sharp carbide tools, high speed and flood coolant; gummy and prone to built-up edge in O/T42.
Can 2219-T31 be welded?
Yes — weldability is rated excellent (85/100). Best weldable 2xxx alloy — GTAW/GMAW/EBW/FSW with 2319 filler; welds are quench-sensitive, expect ~60–70 % of parent strength unless post-weld solution + age is possible.
What surface finishes work on 2219-T31?
Use chromic or thin sulfuric anodize plus primer for corrosion protection (Cu content darkens film); alkaline cleaning must be short to avoid intergranular attack; not suitable for bright decorative anodizing.
Can 2219-T31 be formed, bent or molded?
Form in O or T31/T42; T87 plate has low cold formability and should be brake-formed with generous radii or hot-formed 150–200 °C.
What is the maximum service temperature of 2219-T31?
2219-T31 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 2219-T87 and 2219-O?
T87 is the default condition — the classic launch-vehicle cryogenic tank plate temper: highest 2219 strength with good weld and cryogenic performance. O: softest, most formable condition for deep forming or before re-solution treatment; annealed at ~415 °C with slow cool. Yield strength is 393 MPa in T87 versus 76 MPa in O.
Can FabDigit make parts in 2219-T31?
Yes — 2219-T31 is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- Aluminum Association Teal Sheets — International Alloy Designations and Chemical Composition Limits — The Aluminum Association (2018)
- ASTM B209 / B209M — Aluminum Sheet and Plate — ASTM (2021)
- AMS-QQ-A-250/30 — 2219 Aluminum Alloy Plate and Sheet — SAE (2016)
- AMS 4143 / AMS 4144 — 2219 Forgings (T6, T852) — SAE (2017)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- MMPDS-2023 Metallic Materials Properties Development and Standardization — FAA/Battelle (2023)
- MatWeb alloy data sheets — Aluminum 2219 tempers — MatWeb LLC (2024)
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.