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Aluminum 356 vs AL9

Aluminum · grade comparison

Aluminum 356 and AL9 are both aluminum grades. 356 is the stronger of the two: tensile strength 262 MPa (38 ksi) against 240 MPa (34.8 ksi) for AL9, about 9% more. 356 is the more ductile: elongation 5% versus 4% for AL9. On the shop floor, 356 machines more easily (very good vs good) and 356 sits in a lower cost tier (budget, $) than AL9 (standard, $$).

356Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

356 vs AL9: properties

356AL9

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

71 GPa10.3 Msi
75 GPa10.9 Msi

Tensile Strength (Ultimate)

262 MPa38 ksi
240 MPa34.8 ksi

Yield Strength (0.2% offset)

186 MPa27 ksi
185 MPa26.8 ksi

Elongation at Break

5%
4%

Compressive Strength

190 MPa27.6 ksi
—

Shear Strength

179 MPa26 ksi
180 MPa26.1 ksi

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
4 J3 ft·lbf

Hardness, Vickers

—
85 HV

Same in both: Elastic (Young's) Modulus 72.4 GPa10.5 Msi · Shear Modulus 27 GPa3.9 Msi · Poisson's Ratio 0.33 · Fatigue Strength (Endurance Limit) 90 MPa13.1 ksi · Fracture Toughness (K_IC) 20 MPa·√m18.2 ksi·√in · Hardness, Brinell 80 HB

Physical

Density and transition temperatures.

Density

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

Same in both: Melting Point (Solidus) 557°C1,035 °F · Liquidus Temperature 613°C1,135 °F

Thermal

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

Same in both: Thermal Conductivity 151 W/m·K87.2 BTU/hr·ft·°F · 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 · Max Service Temperature (continuous) 150°C302 °F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 39 % IACS · Electrical Resistivity 4.4×10⁻⁸ Ω·m1.73 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

62 / 100
58 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.83 V

Manufacturability

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

Machinability

70 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

120%
60%

Weldability

78 / 100
80 / 100

Castability

95 / 100
92 / 100

Brazeability / Solderability

30 / 100
35 / 100

Polishability

45 / 100
50 / 100

Same in both: Formability (cold) 10 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12.5 kg CO₂/kg
12 kg CO₂/kg

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Water 1,200 L/kg144 gal/lb · Typical Recycled Content 60%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

98 kN·m/kg
90 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
27 MN·m/kg

Modulus of Resilience

239 kJ/m³
236 kJ/m³

Thermal Diffusivity

58.7 mm²/s
58.5 mm²/s

Thermal Shock Resistance Index

25
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 scale356AL9

Manufacturing and finishing

Capability356AL9
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.

356 vs AL9 — frequently asked

Is 356 stronger than AL9?

Yes. 356 has a typical tensile strength of 262 MPa (38 ksi) against 240 MPa (34.8 ksi) for AL9 — about 9% more.

Which is cheaper, 356 or AL9?

356 is the lower-cost material: it sits in the budget tier ($) while AL9 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, 356 or AL9?

356. Its machinability rates very good (70/100) against good (60/100) for AL9.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 356 and AL9 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.