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Aluminum AC2A vs AC8A

Aluminum · grade comparison

Aluminum AC2A and AC8A are both aluminum grades. AC8A is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 170 MPa (24.7 ksi) for AC2A, about 41% more; tensile strength follows at 285 MPa (41.3 ksi) vs 250 MPa (36.3 ksi). In exchange, AC2A is the more ductile: elongation 2% versus 1% for AC8A, and AC8A is harder (115 HB vs 85 HB). AC8A is lighter (2.7 g/cm³ vs 2.79 g/cm³ for AC2A) and AC8A is stiffer (82 GPa vs 74 GPa). On the shop floor, AC2A machines more easily (very good vs fair) and AC2A welds better (fair vs poor).

AC2AChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

AC8AChoose it when strength drives the design, or when weight is the constraint.

AC2A vs AC8A: properties

AC2AAC8A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
82 GPa11.9 Msi

Shear Modulus

27.5 GPa4 Msi
27 GPa3.9 Msi

Bulk Modulus

72 GPa10.4 Msi
76 GPa11 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
285 MPa41.3 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
240 MPa34.8 ksi

Elongation at Break

2%
1%

Shear Strength

165 MPa23.9 ksi
195 MPa28.3 ksi

Fatigue Strength (Endurance Limit)

75 MPa10.9 ksi
95 MPa13.8 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
16 MPa·√m14.6 ksi·√in

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
3 J1.8 ft·lbf

Hardness, Brinell

85 HB
115 HB

Compressive Strength

—
340 MPa49.3 ksi

Hardness, Rockwell B

—
65 HRB

Hardness, Vickers

—
120 HV

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.79 g/cm³0.1 lb/in³
2.7 g/cm³0.1 lb/in³

Melting Point (Solidus)

516°C961 °F
525°C977 °F

Liquidus Temperature

604°C1,119 °F
580°C1,076 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

110 W/m·K63.6 BTU/hr·ft·°F
130 W/m·K75.1 BTU/hr·ft·°F

Specific Heat Capacity

963 J/kg·K0.23 BTU/lb·°F
880 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
19.5 µm/m·K10.8 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
470 J/g202 BTU/lb

Max Service Temperature (continuous)

175°C347 °F
250°C482 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
28 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
6.2×10⁻⁸ Ω·m2.44 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.75 V
-0.78 V

Corrosion Resistance

42 / 100
36 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

72 / 100
50 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
45%

Weldability

35 / 100
25 / 100

Formability (cold)

10 / 100
4 / 100

Castability

75 / 100
85 / 100

Brazeability / Solderability

25 / 100
20 / 100

Polishability

40 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

1,150 L/kg138 gal/lb
1,200 L/kg144 gal/lb

Typical Recycled Content

80%
60%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

90 kN·m/kg
106 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
30.4 MN·m/kg

Modulus of Resilience

195 kJ/m³
351 kJ/m³

Thermal Diffusivity

40.9 mm²/s
54.7 mm²/s

Thermal Shock Resistance Index

17
23

Strength versus weight

Yield strength against density for every aluminum grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scaleAC2AAC8A

Manufacturing and finishing

CapabilityAC2AAC8A
Default condition——
Relative cost$$ Standard$$ Standard
Min. machined wall——
Best machined surface——

Both take the same 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

AC2A vs AC8A — frequently asked

Is AC8A stronger than AC2A?

Yes. AC8A has a typical yield strength of 240 MPa (34.8 ksi) against 170 MPa (24.7 ksi) for AC2A — about 41% more. Tensile strength is 285 MPa (41.3 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, AC2A or AC8A?

Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, AC2A or AC8A?

AC2A. Its machinability rates very good (72/100) against fair (50/100) for AC8A; for welding the order is AC2A first (fair, 35/100) then AC8A (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2A and AC8A side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.

Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.