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Aluminum 2018-F (As fabricated)

Temper

AA 2018 · UNS A92018

As-forged stock with no controlled thermal treatment; properties vary with section and are not guaranteed, used only as pre-machining blank.

Premium cost $$$

Values for the F condition

Other 2018 tempers and conditions

2018 is listed in 4 conditions; see the grade overview at 2018.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
Annealed
Softest condition, used as intermediate stock for further forging, machining or straightening before heat treatment.701402045 HB46 % IACS
FThis page
As fabricated
As-forged stock with no controlled thermal treatment; properties vary with section and are not guaranteed, used only as pre-machining blank.1402501570 HB44 % IACS
Solution heat treated and naturally aged
Intermediate condition after solution treatment; moderate strength with more ductility, normally aged on to T61 for service.2053501895 HB33 % IACS
T61Default
T6 variant, underaged
The standard supply condition for 2018 forgings; best combination of elevated-temperature strength and dimensional stability for pistons and engine parts.31542012120 HB40 % IACS

What is 2018-F?

2018-F is 2018 in the F temper — as-forged stock with no controlled thermal treatment; properties vary with section and are not guaranteed, used only as pre-machining blank. 2018-F has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Elongation at break is 15% and the elastic modulus is 74 GPa (10.7 Msi). 2018-F has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 507°C (945 °F). T61 is the default condition FabDigit quotes; F is available on request or by drawing note.

Advantages

  • High electrical conductivity — 44 % IACS, better than 85% of aluminum grades
  • Conducts heat well — 172 W/m·K (99.4 BTU/hr·ft·°F), better than 84% of aluminum grades
  • Ductile — tolerates forming and impact — 15%, better than 82% of aluminum grades
  • Tough — resists crack growth — 30 MPa·√m (27.3 ksi·√in), better than 76% of aluminum grades

Limitations

  • Needs corrosion protection — 35/100, worse than 85% of aluminum grades
  • Difficult to weld — 25/100, worse than 76% of aluminum grades

2018-F properties

Typical room-temperature values for 2018-F; 22 are specific to this condition. Other listed values are 2018 reference data and may not represent this condition. Bars are the position among aluminum grades.

Physical3

2018-F has a density of 2.8 g/cm³ (0.101 lb/in³), heavier than 81% of aluminum grades. It melts at 507°C (945 °F).

Density2.8 g/cm³0.1 lb/in³
Melting Point (Solidus)507°C945 °F
Liquidus Temperature638°C1,180 °F

Mechanical13

2018-F has a yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Elongation at break is 15% and the elastic modulus is 74 GPa (10.7 Msi).

Elastic (Young's) Modulus74 GPa10.7 Msi
Shear Modulus28 GPa4.1 Msi
Bulk Modulus76 GPa11 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)250 MPa36.3 ksi
Yield Strength (0.2% offset)140 MPa20.3 ksi
Elongation at Break15%
Compressive Strength145 MPa21 ksi
Shear Strength160 MPa23.2 ksi
Fatigue Strength (Endurance Limit)85 MPa12.3 ksi
Fracture Toughness (K_IC)30 MPa·√m27.3 ksi·√in
Hardness, Brinell70 HB
Hardness, Vickers75 HV

Thermal6

2018-F is rated for continuous service to 150°C (302 °F). It conducts heat at 172 W/m·K (99.4 BTU/hr·ft·°F), better than 84% of aluminum grades. Thermal expansion is 22.3 µm/m·K (12.4 µin/in·°F).

Thermal Conductivity172 W/m·K99.4 BTU/hr·ft·°F
Specific Heat Capacity875 J/kg·K0.21 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)22.3 µm/m·K12.4 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

2018-F conducts electricity at 44 % IACS, better than 85% of aluminum grades.

Electrical Conductivity44 % IACS
Electrical Resistivity3.92×10⁻⁸ Ω·m1.54 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is fair (35/100), worse than 85% of aluminum grades.

Galvanic Potential (seawater, vs SCE)-0.7 V
Corrosion ResistanceFair35/100
Chemical Resistance SummaryPoor in chloride and marine environments (pitting, intergranular attack from Cu/Ni phases); acceptable in dry air, fuels, lubricating oils; attacked by strong acids and alkalis; protect with anodize, chromate or paint.

Sustainability4

Producing a kilogram of 2018-F 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 Water1,200 L/kg144 gal/lb
Typical Recycled Content20%

Manufacturability6

2018-F's machinability is good (55/100, worse than 59% of aluminum grades); weldability poor (25/100); formability fair (50/100).

MachinabilityGood55/100
WeldabilityPoor25/100
Formability (cold)Fair50/100
Brazeability / SolderabilityPoor15/100
PolishabilityFair50/100
Anodizing Responsefair — hard/sulfuric anodizing works for wear protection but Cu+Ni give a dark, mottled non-decorative film with reduced corrosion protection

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

Working with 2018-F

Is 2018 easy to machine?

Machines well in T61 with carbide tooling, high speeds and light feeds; hard Ni/Fe intermetallics accelerate tool wear, so use flood coolant and sharp positive-rake geometry.

Can 2018 be welded?

Not recommended for fusion welding (severe hot cracking in Al-Cu); join by mechanical fasteners or, if unavoidable, resistance/friction-stir with post-weld solution treatment and re-aging.

Can 2018 be formed, bent or molded?

Primarily hot forged at ~400–450 °C; cold formability in T61 is poor — bend or straighten only in O or freshly solution-treated condition.

What surface finishes work on 2018?

Hard anodize for wear surfaces (dark, non-uniform color); chromate conversion or primer + paint recommended for corrosion protection; avoid decorative clear anodize.

2018 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
Cuprincipal strengthener (Al₂Cu)3.5 – 4.54
Nithermally stable Al-Cu-Ni intermetallics1.7 – 2.32
Mg0.45 – 0.90.7
Siimpurity limit≤ 0.9—
Feimpurity limit≤ 1—
Mn≤ 0.2—
Cr≤ 0.1—
Zn≤ 0.25—
Tigrain refiner≤ 0.15—
Others (each)≤ 0.05—
Others (total)≤ 0.15—
Albalance—

2018-F — frequently asked

What is 2018-F used for?

2018-F is typically used for forged pistons, cylinder heads and aircraft engine parts. In short: hot-strength forging alloy; 200 °C service capability; legacy piston-alloy grade.

What is the yield strength of 2018-F?

2018-F has a typical yield strength of 140 MPa (20.3 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 70% of aluminum grades. Strength varies by condition: see the 4 listed tempers.

Is 2018-F easy to machine?

Reasonably — machinability is rated good (55/100, worse than 59% of aluminum grades). Machines well in T61 with carbide tooling, high speeds and light feeds; hard Ni/Fe intermetallics accelerate tool wear, so use flood coolant and sharp positive-rake geometry.

Can 2018-F be welded?

Not readily — weldability is rated poor (25/100). Not recommended for fusion welding (severe hot cracking in Al-Cu); join by mechanical fasteners or, if unavoidable, resistance/friction-stir with post-weld solution treatment and re-aging.

What surface finishes work on 2018-F?

Hard anodize for wear surfaces (dark, non-uniform color); chromate conversion or primer + paint recommended for corrosion protection; avoid decorative clear anodize.

Can 2018-F be formed, bent or molded?

Primarily hot forged at ~400–450 °C; cold formability in T61 is poor — bend or straighten only in O or freshly solution-treated condition.

What is the maximum service temperature of 2018-F?

2018-F 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 2018-T61 and 2018-O?

T61 is the default condition — the standard supply condition for 2018 forgings; best combination of elevated-temperature strength and dimensional stability for pistons and engine parts. O: softest condition, used as intermediate stock for further forging, machining or straightening before heat treatment. Yield strength is 315 MPa in T61 versus 70 MPa in O.

Sources

  1. International Alloy Designations and Chemical Composition Limits for Wrought Aluminum (Teal Sheets) — The Aluminum Association (2018)
  2. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
  3. Aluminum: Properties and Physical Metallurgy (ed. J.E. Hatch) — ASM International (1984)
  4. ASTM B247 — Aluminum-Alloy Die, Hand and Rolled Ring Forgings — ASTM International (2020)

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.