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Aluminum AC2A vs AC5A

Aluminum · grade comparison

Aluminum AC2A and AC5A are both aluminum grades. AC5A is the stronger of the two: yield strength 255 MPa (37 ksi) against 170 MPa (24.7 ksi) for AC2A, about 50% more; tensile strength follows at 295 MPa (42.8 ksi) vs 250 MPa (36.3 ksi). In exchange, AC2A is the more ductile: elongation 2% versus 1% for AC5A, and AC5A is harder (105 HB vs 85 HB). AC5A runs hotter in service (220°C vs 175°C continuous) and AC5A conducts electricity better (30 % IACS vs 27 % IACS). On the shop floor, AC2A welds better (fair vs poor) and AC2A sits in a lower cost tier (standard, $$) than AC5A (premium, $$$).

AC2AChoose it when the part is bent, formed or impact-loaded, or when it will be welded.

AC5AChoose it when strength drives the design, or when the part sees heat.

AC2A vs AC5A: properties

AC2AAC5A

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
27 GPa3.9 Msi

Bulk Modulus

72 GPa10.4 Msi
71 GPa10.3 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
295 MPa42.8 ksi

Yield Strength (0.2% offset)

170 MPa24.7 ksi
255 MPa37 ksi

Elongation at Break

2%
1%

Shear Strength

165 MPa23.9 ksi
200 MPa29 ksi

Fatigue Strength (Endurance Limit)

75 MPa10.9 ksi
68 MPa9.9 ksi

Fracture Toughness (K_IC)

18 MPa·√m16.4 ksi·√in
17 MPa·√m15.5 ksi·√in

Hardness, Brinell

85 HB
105 HB

Compressive Strength

—
265 MPa38.4 ksi

Hardness, Vickers

—
112 HV

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
2.81 g/cm³0.1 lb/in³

Melting Point (Solidus)

516°C961 °F
528°C982 °F

Liquidus Temperature

604°C1,119 °F
635°C1,175 °F

Thermal

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

Thermal Conductivity

110 W/m·K63.6 BTU/hr·ft·°F
122 W/m·K70.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
22.5 µm/m·K12.5 µin/in·°F

Max Service Temperature (continuous)

175°C347 °F
220°C428 °F

Min Service Temperature

-196°C-321 °F
-100°C-148 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
30 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
5.7×10⁻⁸ Ω·m2.24 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.75 V
-0.73 V

Corrosion Resistance

42 / 100
30 / 100

Manufacturability

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

Machinability Rating (AISI 1212 = 100 %)

70%
300%

Weldability

35 / 100
25 / 100

Formability (cold)

10 / 100
5 / 100

Castability

75 / 100
45 / 100

Brazeability / Solderability

25 / 100
15 / 100

Polishability

40 / 100
45 / 100

Same in both: Machinability 72 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
150 MJ/kg64,488 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

80%
35%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

90 kN·m/kg
105 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
25.3 MN·m/kg

Modulus of Resilience

195 kJ/m³
458 kJ/m³

Thermal Diffusivity

40.9 mm²/s
45.1 mm²/s

Thermal Shock Resistance Index

17
23

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 scaleAC2AAC5A

Manufacturing and finishing

CapabilityAC2AAC5A
Default condition——
Relative cost$$ Standard$$$ Premium
Min. machined wall——
Best machined surface——

Both take the same 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

AC2A vs AC5A — frequently asked

Is AC5A stronger than AC2A?

Yes. AC5A has a typical yield strength of 255 MPa (37 ksi) against 170 MPa (24.7 ksi) for AC2A — about 50% more. Tensile strength is 295 MPa (42.8 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, AC2A or AC5A?

AC2A is the lower-cost material: it sits in the standard tier ($$) while AC5A is premium ($$$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which welds better, AC2A or AC5A?

AC2A. Its weldability rates fair (35/100) against poor (25/100) for AC5A.

Ready to make it?

Upload a CAD file and FabDigit prices the part in AC2A and AC5A 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.