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Aluminum AC2A vs AC3A

Aluminum · grade comparison

Aluminum AC2A and AC3A are both aluminum grades. AC2A is the stronger of the two: yield strength 170 MPa (24.7 ksi) against 75 MPa (10.9 ksi) for AC3A, about 127% more; tensile strength follows at 250 MPa (36.3 ksi) vs 165 MPa (23.9 ksi). In exchange, AC3A is the more ductile: elongation 6% versus 2% for AC2A, and AC2A is harder (85 HB vs 50 HB). AC3A is lighter (2.66 g/cm³ vs 2.79 g/cm³ for AC2A) and AC2A runs hotter in service (175°C vs 150°C continuous). On the shop floor, AC2A machines more easily (very good vs fair) and AC3A welds better (very good vs fair).

AC2AChoose it when strength drives the design, or when the part sees heat.

AC3AChoose it when the part is bent, formed or impact-loaded, or when weight is the constraint.

AC2A vs AC3A: properties

AC2AAC3A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
71 GPa10.3 Msi

Shear Modulus

27.5 GPa4 Msi
26.5 GPa3.8 Msi

Bulk Modulus

72 GPa10.4 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
165 MPa23.9 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
75 MPa10.9 ksi

Elongation at Break

2%
6%

Shear Strength

165 MPa23.9 ksi
115 MPa16.7 ksi

Fatigue Strength (Endurance Limit)

75 MPa10.9 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
15 MPa·√m13.7 ksi·√in

Hardness, Brinell

85 HB
50 HB

Same in both: Poisson's Ratio 0.33 · Charpy V-Notch Impact (RT) 3 J2.2 ft·lbf

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

516°C961 °F
574°C1,065 °F

Liquidus Temperature

604°C1,119 °F
582°C1,080 °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

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
20.5 µm/m·K11.4 µin/in·°F

Max Service Temperature (continuous)

175°C347 °F
150°C302 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
33 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
5.2×10⁻⁸ Ω·m2.05 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.75 V
-0.83 V

Corrosion Resistance

42 / 100
58 / 100

Manufacturability

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

Machinability

72 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
30%

Weldability

35 / 100
80 / 100

Castability

75 / 100
95 / 100

Brazeability / Solderability

25 / 100
35 / 100

Polishability

40 / 100
45 / 100

Same in both: Formability (cold) 10 / 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%
70%

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
62 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
26.7 MN·m/kg

Modulus of Resilience

195 kJ/m³
40 kJ/m³

Thermal Diffusivity

40.9 mm²/s
50.7 mm²/s

Thermal Shock Resistance Index

17
15

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 scaleAC2AAC3A

Manufacturing and finishing

CapabilityAC2AAC3A
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 AC3A — frequently asked

Is AC2A stronger than AC3A?

Yes. AC2A has a typical yield strength of 170 MPa (24.7 ksi) against 75 MPa (10.9 ksi) for AC3A — about 127% more. Tensile strength is 250 MPa (36.3 ksi) vs 165 MPa (23.9 ksi).

Which is cheaper, AC2A or AC3A?

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 AC3A?

AC2A. Its machinability rates very good (72/100) against fair (40/100) for AC3A; for welding the order is AC3A first (very good, 80/100) then AC2A (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2A and AC3A 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.