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Aluminum AC2B vs AC3A

Aluminum · grade comparison

Aluminum AC2B and AC3A are both aluminum grades. AC2B is the stronger of the two: yield strength 110 MPa (16 ksi) against 75 MPa (10.9 ksi) for AC3A, about 47% more; tensile strength follows at 180 MPa (26.1 ksi) vs 165 MPa (23.9 ksi). In exchange, AC3A is the more ductile: elongation 6% versus 2% for AC2B, and AC2B is harder (70 HB vs 50 HB). AC3A is lighter (2.66 g/cm³ vs 2.77 g/cm³ for AC2B) and AC3A conducts heat better (130 W/m·K vs 109 W/m·K). On the shop floor, AC2B machines more easily (good vs fair) and AC3A welds better (very good vs fair).

AC2BChoose it when strength drives the design, or when the part is machined in volume.

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

AC2B vs AC3A: properties

AC2BAC3A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
71 GPa10.3 Msi

Shear Modulus

28 GPa4.1 Msi
26.5 GPa3.8 Msi

Bulk Modulus

71 GPa10.3 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

180 MPa26.1 ksi
165 MPa23.9 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
75 MPa10.9 ksi

Elongation at Break

2%
6%

Compressive Strength

115 MPa16.7 ksi
—

Shear Strength

145 MPa21 ksi
115 MPa16.7 ksi

Fatigue Strength (Endurance Limit)

70 MPa10.2 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

17 MPa·√m15.5 ksi·√in
15 MPa·√m13.7 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
3 J2.2 ft·lbf

Hardness, Brinell

70 HB
50 HB

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.77 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

109 W/m·K63 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

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Max Service Temperature (continuous) 150°C302 °F · 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)

-0.81 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

65 / 100
40 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
30%

Weldability

35 / 100
80 / 100

Formability (cold)

5 / 100
10 / 100

Castability

85 / 100
95 / 100

Brazeability / Solderability

20 / 100
35 / 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

85%
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)

65 kN·m/kg
62 kN·m/kg

Modulus of Resilience

82 kJ/m³
40 kJ/m³

Thermal Diffusivity

40.9 mm²/s
50.7 mm²/s

Thermal Shock Resistance Index

12
15

Same in both: Specific Stiffness (E / density) 26.7 MN·m/kg

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 scaleAC2BAC3A

Manufacturing and finishing

CapabilityAC2BAC3A
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.

AC2B vs AC3A — frequently asked

Is AC2B stronger than AC3A?

Yes. AC2B has a typical yield strength of 110 MPa (16 ksi) against 75 MPa (10.9 ksi) for AC3A — about 47% more. Tensile strength is 180 MPa (26.1 ksi) vs 165 MPa (23.9 ksi).

Which is cheaper, AC2B 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, AC2B or AC3A?

AC2B. Its machinability rates good (65/100) against fair (40/100) for AC3A; for welding the order is AC3A first (very good, 80/100) then AC2B (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2B 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.