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Aluminum AC2B vs AC4D

Aluminum · grade comparison

Aluminum AC2B and AC4D are both aluminum grades. AC4D is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for AC2B, about 64% more; tensile strength follows at 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi). AC4D is the more ductile: elongation 2.5% versus 2% for AC2B, and AC4D is harder (88 HB vs 70 HB). AC4D conducts heat better (151 W/m·K vs 109 W/m·K).

AC4DChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AC2B vs AC4D: properties

AC2BAC4D

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
72 GPa10.4 Msi

Tensile Strength (Ultimate)

180 MPa26.1 ksi
250 MPa36.3 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
180 MPa26.1 ksi

Elongation at Break

2%
2.5%

Compressive Strength

115 MPa16.7 ksi
—

Shear Strength

145 MPa21 ksi
193 MPa28 ksi

Fatigue Strength (Endurance Limit)

70 MPa10.2 ksi
62 MPa9 ksi

Fracture Toughness (K_IC)

17 MPa·√m15.5 ksi·√in
20 MPa·√m18.2 ksi·√in

Hardness, Brinell

70 HB
88 HB

Same in both: Poisson's Ratio 0.33 · Charpy V-Notch Impact (RT) 4 J3 ft·lbf

Physical

Density and transition temperatures.

Density

2.77 g/cm³0.1 lb/in³
2.71 g/cm³0.1 lb/in³

Melting Point (Solidus)

516°C961 °F
549°C1,020 °F

Liquidus Temperature

604°C1,119 °F
621°C1,150 °F

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
151 W/m·K87.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
22.3 µm/m·K12.4 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
425 J/g183 BTU/lb

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
39 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
4.42×10⁻⁸ Ω·m1.74 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.81 V
-0.78 V

Corrosion Resistance

42 / 100
45 / 100

Manufacturability

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

Machinability

65 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
180%

Weldability

35 / 100
40 / 100

Formability (cold)

5 / 100
10 / 100

Castability

85 / 100
78 / 100

Brazeability / Solderability

20 / 100
25 / 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
92 kN·m/kg

Specific Stiffness (E / density)

26.7 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

82 kJ/m³
228 kJ/m³

Thermal Diffusivity

40.9 mm²/s
57.9 mm²/s

Thermal Shock Resistance Index

12
24

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 scaleAC2BAC4D

Manufacturing and finishing

CapabilityAC2BAC4D
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 AC4D — frequently asked

Is AC4D stronger than AC2B?

Yes. AC4D has a typical yield strength of 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for AC2B — about 64% more. Tensile strength is 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi).

Which is cheaper, AC2B or AC4D?

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 welds better, AC2B or AC4D?

AC4D. Its weldability rates fair (40/100) against fair (35/100) for AC2B.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2B and AC4D 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.