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Aluminum AC2A vs AC4CH

Aluminum · grade comparison

Aluminum AC2A and AC4CH are both aluminum grades. AC4CH is the stronger of the two: yield strength 210 MPa (30.5 ksi) against 170 MPa (24.7 ksi) for AC2A, about 24% more; tensile strength follows at 280 MPa (40.6 ksi) vs 250 MPa (36.3 ksi). AC4CH is the more ductile: elongation 8% versus 2% for AC2A. AC4CH is lighter (2.68 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 good) and AC4CH welds better (very good vs fair).

AC2AChoose it when the part sees heat, or when the part is machined in volume.

AC4CHChoose it when strength drives the design, or when the part is bent, formed or impact-loaded.

AC2A vs AC4CH: properties

AC2AAC4CH

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
72.4 GPa10.5 Msi

Shear Modulus

27.5 GPa4 Msi
27 GPa3.9 Msi

Bulk Modulus

72 GPa10.4 Msi
71 GPa10.3 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
280 MPa40.6 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
210 MPa30.5 ksi

Elongation at Break

2%
8%

Shear Strength

165 MPa23.9 ksi
200 MPa29 ksi

Fatigue Strength (Endurance Limit)

75 MPa10.9 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
25 MPa·√m22.8 ksi·√in

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
4 J3 ft·lbf

Compressive Strength

—
215 MPa31.2 ksi

Same in both: Poisson's Ratio 0.33 · Hardness, Brinell 85 HB

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

516°C961 °F
557°C1,035 °F

Liquidus Temperature

604°C1,119 °F
613°C1,135 °F

Thermal

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

Thermal Conductivity

110 W/m·K63.6 BTU/hr·ft·°F
151 W/m·K87.2 BTU/hr·ft·°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 · Thermal Expansion (CTE, 20–100 °C) 21.5 µm/m·K11.9 µin/in·°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
39 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
4.4×10⁻⁸ Ω·m1.73 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
55 / 100

Manufacturability

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

Machinability

72 / 100
60 / 100

Weldability

35 / 100
75 / 100

Formability (cold)

10 / 100
15 / 100

Castability

75 / 100
92 / 100

Brazeability / Solderability

25 / 100
30 / 100

Polishability

40 / 100
55 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 70%

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12 kg CO₂/kg
12.5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

80%
20%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

90 kN·m/kg
104 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
27 MN·m/kg

Modulus of Resilience

195 kJ/m³
305 kJ/m³

Thermal Diffusivity

40.9 mm²/s
58.5 mm²/s

Thermal Shock Resistance Index

17
27

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 scaleAC2AAC4CH

Manufacturing and finishing

CapabilityAC2AAC4CH
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 AC4CH — frequently asked

Is AC4CH stronger than AC2A?

Yes. AC4CH has a typical yield strength of 210 MPa (30.5 ksi) against 170 MPa (24.7 ksi) for AC2A — about 24% more. Tensile strength is 280 MPa (40.6 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, AC2A or AC4CH?

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 AC4CH?

AC2A. Its machinability rates very good (72/100) against good (60/100) for AC4CH; for welding the order is AC4CH first (very good, 75/100) then AC2A (fair, 35/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2A and AC4CH 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.