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Aluminum 7022-O (Annealed)

Temper

AA 7022 · EN AlZn5Mg3Cu, 3.4345

Pick for maximum formability or as an intermediate condition before solution treatment; strength is low and must be restored by T6 ageing.

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Values for the O condition

Other 7022 tempers and conditions

7022 is listed in 5 conditions; see the grade overview at 7022.

Compare all 5 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
OThis page
Annealed
Pick for maximum formability or as an intermediate condition before solution treatment; strength is low and must be restored by T6 ageing.1202401568 HB39 % IACS
Solution heat treated and artificially aged
Standard peak-aged condition for extrusions, bar and forgings when maximum static strength is required and residual stress is not critical.4605208148 HB32 % IACS
Solution treated, stress-relieved by stretching, aged; no further…
Choose for extrusions and drawn bar that will be CNC-machined asymmetrically — stretched stress relief with no post-straightening keeps distortion minimal.4655208149 HB32 % IACS
T6, stress relieved by stretching, minor straightening
Same as T6510 but with a small straightening allowance, so it is the usual supply condition for long extruded profiles and rod with tight straightness limits.4655208149 HB32 % IACS
T651Default
T6, stress relieved by stretching
Default stocked condition for thick plate and tooling/mould plate — peak strength with low residual stress so heavily machined parts stay flat.4705308150 HB32 % IACS

What is 7022-O?

7022-O is 7022 in the O temper — pick for maximum formability or as an intermediate condition before solution treatment; strength is low and must be restored by T6 ageing. 7022-O has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 77% of aluminum grades. Elongation at break is 15% and the elastic modulus is 70 GPa (10.2 Msi). 7022-O has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 475°C (887 °F). T651 is the default condition FabDigit quotes; O is available on request or by drawing note.

Advantages

  • Polishes to a fine finish — 72/100, better than 89% of aluminum grades
  • Ductile — tolerates forming and impact — 15%, better than 82% of aluminum grades
  • Conducts heat well — 170 W/m·K (98.2 BTU/hr·ft·°F), better than 82% of aluminum grades
  • Forms and bends easily — 60/100, better than 77% of aluminum grades

Limitations

  • Difficult to weld — 20/100, worse than 89% of aluminum grades
  • Low strength — 120 MPa (17.4 ksi), worse than 77% of aluminum grades

7022-O properties

Typical room-temperature values for 7022-O; 11 are specific to this condition. Other listed values are 7022 reference data and may not represent this condition. Bars are the position among aluminum grades.

Physical3

7022-O has a density of 2.78 g/cm³ (0.1 lb/in³), heavier than 74% of aluminum grades. It melts at 475°C (887 °F).

Density2.78 g/cm³0.1 lb/in³
Melting Point (Solidus)475°C887 °F
Liquidus Temperature635°C1,175 °F

Mechanical15

7022-O has a yield strength of 120 MPa (17.4 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 77% of aluminum grades. Elongation at break is 15% and the elastic modulus is 70 GPa (10.2 Msi).

Elastic (Young's) Modulus70 GPa10.2 Msi
Shear Modulus26.5 GPa3.8 Msi
Bulk Modulus71 GPa10.3 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)240 MPa34.8 ksi
Yield Strength (0.2% offset)120 MPa17.4 ksi
Elongation at Break15%
Reduction in Area18%
Compressive Strength480 MPa69.6 ksi
Shear Strength155 MPa22.5 ksi
Fatigue Strength (Endurance Limit)150 MPa21.8 ksi
Fracture Toughness (K_IC)28 MPa·√m25.5 ksi·√in
Hardness, Brinell68 HB
Hardness, Rockwell B85 HRB
Hardness, Vickers160 HV

Thermal6

7022-O is rated for continuous service to 150°C (302 °F). It conducts heat at 170 W/m·K (98.2 BTU/hr·ft·°F), better than 82% of aluminum grades. Thermal expansion is 23.5 µm/m·K (13.1 µin/in·°F).

Thermal Conductivity170 W/m·K98.2 BTU/hr·ft·°F
Specific Heat Capacity865 J/kg·K0.21 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)23.5 µm/m·K13.1 µin/in·°F
Latent Heat of Fusion390 J/g168 BTU/lb
Max Service Temperature (continuous)150°C302 °F
Min Service Temperature-196°C-321 °F

Electrical3

7022-O conducts electricity at 39 % IACS, better than 65% of aluminum grades.

Electrical Conductivity39 % IACS
Electrical Resistivity5.4×10⁻⁸ Ω·m2.13 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is good (55/100), worse than 51% of aluminum grades.

Galvanic Potential (seawater, vs SCE)-0.84 V
Corrosion ResistanceGood55/100
Chemical Resistance SummaryGood in neutral water and dry atmospheres; attacked by strong acids and alkalis, and the peak-aged temper is prone to stress-corrosion cracking in chloride environments — protect with anodising, cladding or paint.

Sustainability4

Producing a kilogram of 7022-O takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 20%.

Embodied Energy (primary production)200 MJ/kg85,985 BTU/lb
Embodied Carbon (primary production)12.5 kg CO₂/kg
Embodied Water1,100 L/kg132 gal/lb
Typical Recycled Content20%

Manufacturability8

7022-O's machinability is fair (45/100, worse than 72% of aluminum grades); weldability poor (20/100); formability good (60/100).

MachinabilityFair45/100
Machinability Rating (AISI 1212 = 100 %)300%
WeldabilityPoor20/100
Formability (cold)Good60/100
CastabilityFair35/100
Brazeability / SolderabilityPoor15/100
PolishabilityVery good72/100
Anodizing Responsegood — hard (Type III) and sulphuric anodising both work well; decorative clear coatings come out slightly grey/yellow because of the Zn-Mg-Cu content.

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 7022-O

Is 7022 easy to machine?

Machines very freely in T6/T651 with sharp polished-flute carbide, high speed and copious coolant; chips are short and surfaces take a fine finish.

Can 7022 be welded?

Not recommended for fusion welding because of the Cu content (hot cracking and severe HAZ loss); use mechanical fastening, adhesive bonding or friction stir where qualified.

Can 7022 be formed, bent or molded?

Form in the O or freshly solution-treated condition — T6/T651 material has low ductility and generous bend radii are mandatory; hot forge above ~400 °C.

What surface finishes work on 7022?

Responds well to hard and sulphuric anodising (slightly grey tone), chromate/chrome-free conversion coating and paint; polish before anodising for mould surfaces.

7022 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.

ElementSpec limit (wt %)Nominal
Si≤ 0.50.15
Fe≤ 0.50.25
Cu0.5 – 10.75
Mn0.1 – 0.40.25
Mg2.6 – 3.73.1
Cr0.1 – 0.30.2
Zn4.3 – 5.24.8
TiTi (+Zr where specified) limited as grain-refiner residual≤ 0.20.03
Others (each)0.15 % total≤ 0.05—
Albalance—

7022-O — frequently asked

What is 7022-O used for?

7022-O is typically used for structural forgings, military vehicle components and high-strength extrusions. In short: stronger than 7020; forging and extrusion grade; not arc weldable.

What is the yield strength of 7022-O?

7022-O has a typical yield strength of 120 MPa (17.4 ksi) and a tensile strength of 240 MPa (34.8 ksi) — weaker than 77% of aluminum grades. Strength varies by condition: see the 5 listed tempers.

Is 7022-O easy to machine?

Reasonably — machinability is rated fair (45/100, worse than 72% of aluminum grades). Machines very freely in T6/T651 with sharp polished-flute carbide, high speed and copious coolant; chips are short and surfaces take a fine finish.

Can 7022-O be welded?

Not readily — weldability is rated poor (20/100). Not recommended for fusion welding because of the Cu content (hot cracking and severe HAZ loss); use mechanical fastening, adhesive bonding or friction stir where qualified.

What surface finishes work on 7022-O?

Responds well to hard and sulphuric anodising (slightly grey tone), chromate/chrome-free conversion coating and paint; polish before anodising for mould surfaces.

Can 7022-O be formed, bent or molded?

Form in the O or freshly solution-treated condition — T6/T651 material has low ductility and generous bend radii are mandatory; hot forge above ~400 °C.

What is the maximum service temperature of 7022-O?

7022-O 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 7022-T651 and 7022-O?

T651 is the default condition — default stocked condition for thick plate and tooling/mould plate — peak strength with low residual stress so heavily machined parts stay flat. O: pick for maximum formability or as an intermediate condition before solution treatment; strength is low and must be restored by T6 ageing. Yield strength is 470 MPa in T651 versus 120 MPa in O.

Sources

  1. EN 573-3 Aluminium and aluminium alloys — chemical composition — CEN (2019)
  2. EN 485-2 Aluminium sheet, strip and plate — mechanical properties — CEN (2018)
  3. EN 755-2 Aluminium extruded rod/bar, tube and profiles — mechanical properties — CEN (2016)
  4. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
  5. ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
  6. High-strength AlZnMgCu (7022-type) mould plate datasheets — European aluminium plate producers (2022)

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.