Aluminum 2139
AA 2139 · UNS A92139
2139 (UNS A92139) is an Al-Cu-Mg-Ag plate alloy in the 2000-series family, where the silver addition promotes a fine strengthening dispersion for improved fatigue and fracture toughness.
Reference datasheet — 2139 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the T8 condition
2139 tempers and conditions
2139 is supplied in 6 conditions, soft to hard. T8 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Softest condition for severe forming or intermediate processing; must be re-heat-treated to reach strength. | 85 | 195 | 18 | 50 HB | 47 % IACS |
Solution heat treated and naturally aged | Use when moderate strength with better ductility is needed, or as the condition for forming before artificial ageing. | 275 | 430 | 20 | 115 HB | 30 % IACS |
Solution heat treated, cold worked and naturally aged | Naturally aged plate/sheet condition when high toughness and formability matter more than peak yield strength. | 315 | 455 | 17 | 125 HB | 30 % IACS |
Solution heat treated and artificially aged | Peak-aged without prior stretching — used for forgings and machined parts where residual stress control is by machining strategy. | 415 | 470 | 9 | 130 HB | 36 % IACS |
T8, stress relieved by stretching | Choose for thick plate that will be heavily machined — stretch stress relief minimises distortion of machined structural parts. | 448 | 480 | 10 | 134 HB | 38 % IACS |
T8Default Solution heat treated, cold worked and artificially aged | The standard supply condition: best combination of strength, fracture toughness and fatigue crack growth resistance for fuselage and armour plate. | 450 | 485 | 11 | 135 HB | 37 % IACS |
What is 2139?
2139 (UNS A92139) is an Al-Cu-Mg-Ag plate alloy in the 2000-series family, where the silver addition promotes a fine strengthening dispersion for improved fatigue and fracture toughness. In the default T8-type condition it gives 450 MPa yield, 485 MPa tensile, 11% elongation and 135 HB, with 150 W/m·K thermal conductivity and 37% IACS, supplied mainly as rolled plate for pressurized fuselage structure. It is the best-machining alloy in this Al-Li/Al-Cu group (score 72) but has low formability (25) and the weakest corrosion resistance here (32), with a 150 °C service ceiling. 2024-T351 plate is the conventional substitute where damage tolerance requirements are lower. 2139 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 96% of aluminum grades. It melts at 507°C (945 °F). 2139 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 485 MPa (70.3 ksi) — stronger than 92% of aluminum grades. Elongation at break is 11% and the elastic modulus is 72 GPa (10.4 Msi).
What is 2139 used for?
- Fuselage plate
- Pressure bulkheads
- Machined skin panels with integral stiffeners
- Armor and blast-resistant structural plate
- Wing and fuselage frames
- Damage-tolerant structural fittings
Advantages
- Tough — resists crack growth — 45 MPa·√m (41 ksi·√in), better than 100% of aluminum grades
- High strength — 450 MPa (65.3 ksi), better than 92% of aluminum grades
- Easy to machine — 72/100, better than 80% of aluminum grades
Limitations
- Needs corrosion protection — 32/100, worse than 94% of aluminum grades
- Difficult to weld — 20/100, worse than 89% of aluminum grades
2139 properties
Typical room-temperature values for 2139-T8; bars are the position among aluminum grades.
Physical3
2139 has a density of 2.85 g/cm³ (0.103 lb/in³), heavier than 96% of aluminum grades. It melts at 507°C (945 °F).
Mechanical12
2139 has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 485 MPa (70.3 ksi) — stronger than 92% of aluminum grades. Elongation at break is 11% and the elastic modulus is 72 GPa (10.4 Msi).
Thermal6
2139 is rated for continuous service to 150°C (302 °F). It conducts heat at 150 W/m·K (86.7 BTU/hr·ft·°F), better than 58% of aluminum grades. Thermal expansion is 22.7 µm/m·K (12.6 µin/in·°F).
Electrical3
2139 conducts electricity at 37 % IACS, better than 58% of aluminum grades.
Chemical & Environmental3
Corrosion resistance is poor (32/100), worse than 94% of aluminum grades.
Sustainability4
Producing a kilogram of 2139 takes about 205 MJ of energy and emits 12.5 kg of CO₂ — more than 76% of aluminum grades. Typical recycled content is 12%.
Manufacturability8
2139's machinability is very good (72/100, better than 80% of aluminum grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the aluminum family
Yield strength against density for every aluminum grade FabDigit runs. 2139 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 2139
Is 2139 easy to machine?
Machines well in T8 with sharp carbide tooling, high speeds and flood coolant; low Fe/Si content gives clean surfaces, and stretch-relieved T851 plate is preferred for deep pocket milling to limit distortion.
Can 2139 be welded?
Not suitable for fusion (GTAW/GMAW) welding — hot cracking and toughness loss; join by riveting/bolting or use friction stir welding, which retains most base-metal properties.
Can 2139 be formed, bent or molded?
Form in O or T4/T3 condition; T8 plate has limited bend ductility and needs generous radii, warm forming or age-forming for contoured skins.
2139 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 | 4.5 – 5.5 | 5 |
| Mg | 0.2 – 0.8 | 0.5 |
| Agkey micro-alloying addition (Ω-phase former) | 0.15 – 0.6 | 0.4 |
| Mn | 0.2 – 0.6 | 0.3 |
| Siimpurity limit for toughness | ≤ 0.1 | |
| Feimpurity limit for toughness | ≤ 0.15 | |
| Zn | ≤ 0.25 | |
| Ti | ≤ 0.15 | |
| Others (each)others total 0.15 max | ≤ 0.05 | |
| Al | balance |
What surface finishes work on 2139?
Chromic or boric-sulphuric anodize plus epoxy primer, or Alclad/spray-coat protection; bare Cu-rich surfaces pit in chlorides, and cosmetic sulphuric anodize gives grey, non-uniform colour.
Surface treatments FabDigit runs on aluminum parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Equivalent designations
Standards and trade names that resolve to Aluminum 2139 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- A92139
How much does 2139 cost?
2139 is a high-cost aluminum ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
2139 — frequently asked
What is 2139 used for?
2139 is typically used for fuselage plate, pressure bulkheads, machined skin panels with integral stiffeners, armor and blast-resistant structural plate, wing and fuselage frames and damage-tolerant structural fittings. In short: silver-modified Al-Cu plate; best machinability in group; damage-tolerant fuselage alloy.
What is the yield strength of 2139?
2139 has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 485 MPa (70.3 ksi) — stronger than 92% of aluminum grades. Strength varies by condition: see the 6 listed tempers.
Is 2139 easy to machine?
Yes — machinability is rated very good (72/100, better than 80% of aluminum grades). Machines well in T8 with sharp carbide tooling, high speeds and flood coolant; low Fe/Si content gives clean surfaces, and stretch-relieved T851 plate is preferred for deep pocket milling to limit distortion.
Can 2139 be welded?
Not readily — weldability is rated poor (20/100). Not suitable for fusion (GTAW/GMAW) welding — hot cracking and toughness loss; join by riveting/bolting or use friction stir welding, which retains most base-metal properties.
What surface finishes work on 2139?
Chromic or boric-sulphuric anodize plus epoxy primer, or Alclad/spray-coat protection; bare Cu-rich surfaces pit in chlorides, and cosmetic sulphuric anodize gives grey, non-uniform colour.
Can 2139 be formed, bent or molded?
Form in O or T4/T3 condition; T8 plate has limited bend ductility and needs generous radii, warm forming or age-forming for contoured skins.
What is the maximum service temperature of 2139?
2139 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 2139-T8 and 2139-O?
T8 is the default condition — the standard supply condition: best combination of strength, fracture toughness and fatigue crack growth resistance for fuselage and armour plate. O: softest condition for severe forming or intermediate processing; must be re-heat-treated to reach strength. Yield strength is 450 MPa in T8 versus 85 MPa in O.
How much does 2139 cost?
2139 is a high-cost aluminum ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
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 — ASM International (1990)
- MMPDS-style typical property data for 2000-series aerospace plate — Battelle/FAA (2023)
- 2139-T8 high-toughness aluminium plate data (Al-Cu-Mg-Ag) — Alcoa/Constellium (aerospace plate producers) (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.