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Aluminum 355 vs AL2

Aluminum · grade comparison

Aluminum 355 and AL2 are both aluminum grades. 355 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 75 MPa (10.9 ksi) for AL2, about 140% more; tensile strength follows at 250 MPa (36.3 ksi) vs 150 MPa (21.8 ksi). In exchange, AL2 is the more ductile: elongation 5% versus 3% for 355, and 355 is harder (85 HB vs 50 HB). 355 runs hotter in service (175°C vs 150°C continuous) and 355 conducts heat better (151 W/m·K vs 121 W/m·K). On the shop floor, 355 machines more easily (good vs fair), AL2 welds better (very good vs good), and 355 sits in a lower cost tier (budget, $) than AL2 (standard, $$).

355Choose it when strength drives the design, or when the part sees heat.

AL2Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

355 vs AL2: properties

355AL2

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

69 GPa10 Msi
68 GPa9.9 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
150 MPa21.8 ksi

Yield Strength (0.2% offset)

180 MPa26.1 ksi
75 MPa10.9 ksi

Elongation at Break

3%
5%

Shear Strength

195 MPa28.3 ksi
110 MPa16 ksi

Fatigue Strength (Endurance Limit)

62 MPa9 ksi
55 MPa8 ksi

Fracture Toughness (K_IC)

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

Hardness, Brinell

85 HB
50 HB

Charpy V-Notch Impact (RT)

—
3 J2.2 ft·lbf

Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

546°C1,015 °F
574°C1,065 °F

Liquidus Temperature

621°C1,150 °F
582°C1,080 °F

Thermal

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

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
121 W/m·K69.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

22.4 µm/m·K12.4 µin/in·°F
20.4 µm/m·K11.3 µin/in·°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 · Latent Heat of Fusion 389 J/g167 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

36 % IACS
31 % IACS

Electrical Resistivity

4.8×10⁻⁸ Ω·m1.89 µΩ·in
5.6×10⁻⁸ Ω·m2.2 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.83 V

Corrosion Resistance

45 / 100
62 / 100

Manufacturability

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

Machinability

62 / 100
35 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
30%

Weldability

55 / 100
80 / 100

Formability (cold)

5 / 100
8 / 100

Castability

85 / 100
96 / 100

Brazeability / Solderability

25 / 100
40 / 100

Polishability

45 / 100
40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12 kg CO₂/kg
11.5 kg CO₂/kg

Embodied Water

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

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Typical Recycled Content 80%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

92 kN·m/kg
57 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

228 kJ/m³
40 kJ/m³

Thermal Diffusivity

57.9 mm²/s
47.4 mm²/s

Thermal Shock Resistance Index

24
13

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 scale355AL2

Manufacturing and finishing

Capability355AL2
CNC machiningYes—
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
DLCYes—
E-CoatingYes—
ElectropolishingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

355 vs AL2 — frequently asked

Is 355 stronger than AL2?

Yes. 355 has a typical yield strength of 180 MPa (26.1 ksi) against 75 MPa (10.9 ksi) for AL2 — about 140% more. Tensile strength is 250 MPa (36.3 ksi) vs 150 MPa (21.8 ksi).

Which is cheaper, 355 or AL2?

355 is the lower-cost material: it sits in the budget tier ($) while AL2 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

Which is easier to machine, 355 or AL2?

355. Its machinability rates good (62/100) against fair (35/100) for AL2; for welding the order is AL2 first (very good, 80/100) then 355 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 355 and AL2 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.