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Aluminum 771.0-F (As fabricated)

Temper

AA 771.0 · UNS A07710 · also 71A

As-poured condition; used only as the starting point for aging or where strength is not critical.

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Values for the F condition

Other 771.0 tempers and conditions

771.0 is listed in 8 conditions; see the grade overview at 771.0.

Compare all 8 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
FThis page
As fabricated
As-poured condition; used only as the starting point for aging or where strength is not critical.125200360 HB32 % IACS
Cooled from hot working, cold worked and naturally aged
Choose when dimensional stability and machining freedom matter more than strength.150220270 HB38 % IACS
T5, stress relieved by stretching
Mild age used mainly to relieve casting stress and stabilize dimensions with modest strengthening.186220370 HB36 % IACS
T5, stress relieved by compression
Best compromise of dimensional stability and moderate strength for machined housings and fixtures.2072481.570 HB36 % IACS
As-cast plus modified stabilizing/aging cycle
Registered variant of the T52 cycle giving similar strength with tighter dimensional control.2072481.570 HB36 % IACS
Solution heat treated and artificially aged
Full heat treatment for the best strength–ductility balance when quench distortion can be tolerated.241290575 HB32 % IACS
Cooled from hot working and artificially aged
Highest strength without any solution treatment/quench — the classic low-distortion route for complex castings.2622901.585 HB34 % IACS
T71Default
Solution heat treated and overaged
Highest-strength, most dimensionally stable and most SCC-resistant temper — the usual production condition for 771.0 castings.310330290 HB35 % IACS

What is 771.0-F?

771.0-F is 771.0 in the F temper — as-poured condition; used only as the starting point for aging or where strength is not critical. 771.0-F has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi). 771.0-F has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 604°C (1,119 °F). T71 is the default condition FabDigit quotes; F is available on request or by drawing note.

Advantages

  • Polishes to a fine finish — 70/100, better than 87% of aluminum grades

Limitations

  • Limited service temperature — 100°C (212 °F), worse than 91% of aluminum grades
  • Poor heat conductor — 119 W/m·K (68.8 BTU/hr·ft·°F), worse than 81% of aluminum grades
  • Limited ductility — 3%, worse than 79% of aluminum grades
  • Low strength — 125 MPa (18.1 ksi), worse than 75% of aluminum grades

771.0-F properties

Typical room-temperature values for 771.0-F; 20 are specific to this condition. Other listed values are 771.0 reference data and may not represent this condition. Bars are the position among aluminum grades.

Physical3

771.0-F has a density of 2.81 g/cm³ (0.102 lb/in³), heavier than 86% of aluminum grades. It melts at 604°C (1,119 °F).

Density2.81 g/cm³0.1 lb/in³
Melting Point (Solidus)604°C1,119 °F
Liquidus Temperature643°C1,189 °F

Mechanical10

771.0-F has a yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Elongation at break is 3% and the elastic modulus is 71 GPa (10.3 Msi).

Elastic (Young's) Modulus71 GPa10.3 Msi
Shear Modulus26.5 GPa3.8 Msi
Bulk Modulus70 GPa10.2 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)200 MPa29 ksi
Yield Strength (0.2% offset)125 MPa18.1 ksi
Elongation at Break3%
Shear Strength130 MPa18.9 ksi
Fatigue Strength (Endurance Limit)50 MPa7.3 ksi
Hardness, Brinell60 HB

Thermal6

771.0-F is rated for continuous service to 100°C (212 °F). It conducts heat at 119 W/m·K (68.8 BTU/hr·ft·°F), worse than 81% of aluminum grades. Thermal expansion is 24 µm/m·K (13.3 µin/in·°F).

Thermal Conductivity119 W/m·K68.8 BTU/hr·ft·°F
Specific Heat Capacity960 J/kg·K0.23 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)24 µm/m·K13.3 µin/in·°F
Latent Heat of Fusion390 J/g168 BTU/lb
Max Service Temperature (continuous)100°C212 °F
Min Service Temperature-196°C-321 °F

Electrical3

771.0-F conducts electricity at 32 % IACS, worse than 63% of aluminum grades.

Electrical Conductivity32 % IACS
Electrical Resistivity5.4×10⁻⁸ Ω·m2.13 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is fair (45/100), worse than 62% of aluminum grades.

Galvanic Potential (seawater, vs SCE)-0.87 V
Corrosion ResistanceFair45/100
Chemical Resistance SummaryGood in dry atmosphere and neutral pH 4–9 media; attacked by strong acids/alkalis, chlorides and mercury; Al-Zn-Mg composition gives stress-corrosion sensitivity in humid/chloride service unless overaged (T71) and protected.

Sustainability4

Producing a kilogram of 771.0-F takes about 200 MJ of energy and emits 12.5 kg of CO₂ — less than 60% of aluminum grades. Typical recycled content is 25%.

Embodied Energy (primary production)200 MJ/kg85,985 BTU/lb
Embodied Carbon (primary production)12.5 kg CO₂/kg
Embodied Water1,200 L/kg144 gal/lb
Typical Recycled Content25%

Manufacturability8

771.0-F's machinability is good (65/100, better than 62% of aluminum grades); weldability fair (45/100); formability poor (15/100).

MachinabilityGood65/100
Machinability Rating (AISI 1212 = 100 %)180%
WeldabilityFair45/100
Formability (cold)Poor15/100
CastabilityFair45/100
Brazeability / SolderabilityPoor20/100
PolishabilityVery good70/100
Anodizing Responsegood — clear and hard anodize both work; Zn-rich matrix gives a slightly grey/cloudy tone versus 5xx.x alloys

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

Working with 771.0-F

Is 771.0 easy to machine?

Excellent — machines to a bright, burr-free finish with polished-flute carbide, high speed and low feed pressure; T5/T71 chip better than as-cast F.

Can 771.0 be welded?

GTAW/GMAW possible with 5356 or 4043 filler, but the Al-Zn-Mg matrix is hot-crack and SCC sensitive; re-age after welding and avoid weld repairs in stressed areas.

Can 771.0 be formed, bent or molded?

Sand and permanent-mold casting only; fluidity is moderate and hot-tear sensitivity high, so use generous fillets, chills and well-fed risering; the alloy self-ages so many parts skip solution treatment.

What surface finishes work on 771.0?

Takes clear and hard anodize well (slightly grey tone), accepts chromate/ trivalent conversion coating and paint; polish before anodizing for cosmetic parts.

771.0 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≤ 0.15—
Fe≤ 0.15—
Cu≤ 0.1—
Mn≤ 0.1—
Mg0.8 – 10.9
Cr0.06 – 0.20.13
Zn6.5 – 7.57
Tigrain refiner0.1 – 0.20.15
Others (each)≤ 0.05—
Others (total)≤ 0.15—
Albalance—

771.0-F — frequently asked

What is 771.0-F used for?

771.0-F is typically used for aircraft castings, instrument housings and structural parts. In short: strongest 7xx.x casting alloy; high strength-to-weight ratio; machines to bright finish.

What is the yield strength of 771.0-F?

771.0-F has a typical yield strength of 125 MPa (18.1 ksi) and a tensile strength of 200 MPa (29 ksi) — weaker than 75% of aluminum grades. Strength varies by condition: see the 8 listed tempers.

Is 771.0-F easy to machine?

Reasonably — machinability is rated good (65/100, better than 62% of aluminum grades). Excellent — machines to a bright, burr-free finish with polished-flute carbide, high speed and low feed pressure; T5/T71 chip better than as-cast F.

Can 771.0-F be welded?

With care — weldability is rated fair (45/100). GTAW/GMAW possible with 5356 or 4043 filler, but the Al-Zn-Mg matrix is hot-crack and SCC sensitive; re-age after welding and avoid weld repairs in stressed areas.

What surface finishes work on 771.0-F?

Takes clear and hard anodize well (slightly grey tone), accepts chromate/ trivalent conversion coating and paint; polish before anodizing for cosmetic parts.

Can 771.0-F be formed, bent or molded?

Sand and permanent-mold casting only; fluidity is moderate and hot-tear sensitivity high, so use generous fillets, chills and well-fed risering; the alloy self-ages so many parts skip solution treatment.

What is the maximum service temperature of 771.0-F?

771.0-F is rated for continuous use to about 100°C (212 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 771.0-T71 and 771.0-F?

T71 is the default condition — highest-strength, most dimensionally stable and most SCC-resistant temper — the usual production condition for 771.0 castings. F: as-poured condition; used only as the starting point for aging or where strength is not critical. Yield strength is 310 MPa in T71 versus 125 MPa in F.

Sources

  1. ASTM B26/B26M — Aluminum-Alloy Sand Castings — ASTM International (2018)
  2. Registration Record of Aluminum Association Alloy Designations and Chemical Composition Limits for Aluminum Alloys in the Form of Castings and Ingot ('Pink Sheets') — The Aluminum Association (2018)
  3. ASM Specialty Handbook: Aluminum and Aluminum Alloys — ASM International (1993)
  4. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
  5. ASM Handbook Vol. 15 — Casting — ASM International (2008)

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.