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Aluminum 356 vs ZL303

Aluminum · grade comparison

Aluminum 356 and ZL303 are both aluminum grades. 356 is the stronger of the two: yield strength 186 MPa (27 ksi) against 95 MPa (13.8 ksi) for ZL303, about 96% more; tensile strength follows at 262 MPa (38 ksi) vs 160 MPa (23.2 ksi). 356 is the more ductile: elongation 5% versus 2.5% for ZL303, and 356 is harder (80 HB vs 60 HB). 356 conducts heat better (151 W/m·K vs 121 W/m·K). On the shop floor, 356 sits in a lower cost tier (budget, $) than ZL303 (standard, $$).

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

356 vs ZL303: properties

356ZL303

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

72.4 GPa10.5 Msi
70 GPa10.2 Msi

Shear Modulus

27 GPa3.9 Msi
26 GPa3.8 Msi

Bulk Modulus

71 GPa10.3 Msi
69 GPa10 Msi

Tensile Strength (Ultimate)

262 MPa38 ksi
160 MPa23.2 ksi

Yield Strength (0.2% offset)

186 MPa27 ksi
95 MPa13.8 ksi

Elongation at Break

5%
2.5%

Compressive Strength

190 MPa27.6 ksi
—

Shear Strength

179 MPa26 ksi
110 MPa16 ksi

Fatigue Strength (Endurance Limit)

90 MPa13.1 ksi
60 MPa8.7 ksi

Fracture Toughness (K_IC)

20 MPa·√m18.2 ksi·√in
18 MPa·√m16.4 ksi·√in

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
—

Hardness, Brinell

80 HB
60 HB

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.67 g/cm³0.1 lb/in³
2.6 g/cm³0.09 lb/in³

Melting Point (Solidus)

557°C1,035 °F
560°C1,040 °F

Liquidus Temperature

613°C1,135 °F
630°C1,166 °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

Specific Heat Capacity

963 J/kg·K0.23 BTU/lb·°F
960 J/kg·K0.23 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
24.5 µm/m·K13.6 µin/in·°F

Same in both: 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.

Electrical Conductivity

39 % IACS
30 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 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)

-0.83 V
-0.87 V

Corrosion Resistance

62 / 100
80 / 100

Manufacturability

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

Machinability

70 / 100
72 / 100

Machinability Rating (AISI 1212 = 100 %)

120%
190%

Weldability

78 / 100
75 / 100

Formability (cold)

10 / 100
15 / 100

Castability

95 / 100
40 / 100

Brazeability / Solderability

30 / 100
20 / 100

Polishability

45 / 100
80 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
195 MJ/kg83,835 BTU/lb

Embodied Carbon (primary production)

12.5 kg CO₂/kg
11.5 kg CO₂/kg

Embodied Water

1,200 L/kg144 gal/lb
1,100 L/kg132 gal/lb

Typical Recycled Content

60%
45%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

98 kN·m/kg
62 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
26.9 MN·m/kg

Modulus of Resilience

239 kJ/m³
64 kJ/m³

Thermal Diffusivity

58.7 mm²/s
48.5 mm²/s

Thermal Shock Resistance Index

25
11

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 scale356ZL303

Manufacturing and finishing

Capability356ZL303
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 ZL303 — frequently asked

Is 356 stronger than ZL303?

Yes. 356 has a typical yield strength of 186 MPa (27 ksi) against 95 MPa (13.8 ksi) for ZL303 — about 96% more. Tensile strength is 262 MPa (38 ksi) vs 160 MPa (23.2 ksi).

Which is cheaper, 356 or ZL303?

356 is the lower-cost material: it sits in the budget tier ($) while ZL303 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.

When should I choose 356 over ZL303?

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

Ready to make it?

Upload a CAD file and FabDigit prices the part in 356 and ZL303 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.