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Aluminum AC2B vs AC9A

Aluminum · grade comparison

Aluminum AC2B and AC9A are both aluminum grades. AC9A is the stronger of the two: yield strength 190 MPa (27.6 ksi) against 110 MPa (16 ksi) for AC2B, about 73% more; tensile strength follows at 210 MPa (30.5 ksi) vs 180 MPa (26.1 ksi). In exchange, AC2B is the more ductile: elongation 2% versus 0.4% for AC9A, and AC9A is harder (135 HB vs 70 HB). AC9A is lighter (2.66 g/cm³ vs 2.77 g/cm³ for AC2B) and AC9A is stiffer (88 GPa vs 74 GPa). On the shop floor, AC2B machines more easily (good vs poor) and AC2B welds better (fair vs poor).

AC2BChoose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

AC9AChoose it when strength drives the design, or when weight is the constraint.

AC2B vs AC9A: properties

AC2BAC9A

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
88 GPa12.8 Msi

Shear Modulus

28 GPa4.1 Msi
34 GPa4.9 Msi

Bulk Modulus

71 GPa10.3 Msi
70 GPa10.2 Msi

Poisson's Ratio

0.33
0.32

Tensile Strength (Ultimate)

180 MPa26.1 ksi
210 MPa30.5 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
190 MPa27.6 ksi

Elongation at Break

2%
0.4%

Compressive Strength

115 MPa16.7 ksi
480 MPa69.6 ksi

Shear Strength

145 MPa21 ksi
160 MPa23.2 ksi

Fatigue Strength (Endurance Limit)

70 MPa10.2 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

17 MPa·√m15.5 ksi·√in
11 MPa·√m10 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
1 J0.74 ft·lbf

Hardness, Brinell

70 HB
135 HB

Reduction in Area

—
0.5%

Hardness, Rockwell B

—
75 HRB

Hardness, Vickers

—
142 HV

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
510°C950 °F

Liquidus Temperature

604°C1,119 °F
700°C1,292 °F

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
120 W/m·K69.3 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
17 µm/m·K9.4 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
440 J/g189 BTU/lb

Max Service Temperature (continuous)

150°C302 °F
250°C482 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
24 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
7.2×10⁻⁸ Ω·m2.83 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
44 / 100

Manufacturability

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

Machinability

65 / 100
25 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
30%

Weldability

35 / 100
20 / 100

Castability

85 / 100
65 / 100

Brazeability / Solderability

20 / 100
25 / 100

Same in both: Formability (cold) 5 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
155 MJ/kg66,638 BTU/lb

Embodied Carbon (primary production)

12 kg CO₂/kg
10.5 kg CO₂/kg

Embodied Water

1,150 L/kg138 gal/lb
1,100 L/kg132 gal/lb

Typical Recycled Content

85%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

65 kN·m/kg
79 kN·m/kg

Specific Stiffness (E / density)

26.7 MN·m/kg
33.1 MN·m/kg

Modulus of Resilience

82 kJ/m³
205 kJ/m³

Thermal Diffusivity

40.9 mm²/s
51.9 mm²/s

Thermal Shock Resistance Index

12
17

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 scaleAC2BAC9A

Manufacturing and finishing

CapabilityAC2BAC9A
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 AC9A — frequently asked

Is AC9A stronger than AC2B?

Yes. AC9A has a typical yield strength of 190 MPa (27.6 ksi) against 110 MPa (16 ksi) for AC2B — about 73% more. Tensile strength is 210 MPa (30.5 ksi) vs 180 MPa (26.1 ksi).

Which is cheaper, AC2B or AC9A?

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 AC9A?

AC2B. Its machinability rates good (65/100) against poor (25/100) for AC9A; for welding the order is AC2B first (fair, 35/100) then AC9A (poor, 20/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2B and AC9A 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.