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Aluminum 356 vs ZL203

Aluminum · grade comparison

Aluminum 356 and ZL203 are both aluminum grades. 356 is the stronger of the two: yield strength 186 MPa (27 ksi) against 110 MPa (16 ksi) for ZL203, about 69% more; tensile strength follows at 262 MPa (38 ksi) vs 215 MPa (31.2 ksi). In exchange, ZL203 is the more ductile: elongation 8% versus 5% for 356, and 356 is harder (80 HB vs 60 HB). 356 is lighter (2.67 g/cm³ vs 2.8 g/cm³ for ZL203) and 356 runs hotter in service (150°C vs 120°C continuous). On the shop floor, ZL203 machines more easily (80 vs 70 out of 100), 356 welds better (very good vs poor), and 356 sits in a lower cost tier (budget, $) than ZL203 (standard, $$).

356Choose it when strength drives the design, or when weight is the constraint.

ZL203Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.

356 vs ZL203: properties

356ZL203

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
215 MPa31.2 ksi

Yield Strength (0.2% offset)

186 MPa27 ksi
110 MPa16 ksi

Elongation at Break

5%
8%

Compressive Strength

190 MPa27.6 ksi
115 MPa16.7 ksi

Shear Strength

179 MPa26 ksi
165 MPa23.9 ksi

Fatigue Strength (Endurance Limit)

90 MPa13.1 ksi
55 MPa8 ksi

Charpy V-Notch Impact (RT)

5 J3.7 ft·lbf
—

Hardness, Brinell

80 HB
60 HB

Same in both: Poisson's Ratio 0.33 · Fracture Toughness (K_IC) 20 MPa·√m18.2 ksi·√in

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

557°C1,035 °F
545°C1,013 °F

Liquidus Temperature

613°C1,135 °F
635°C1,175 °F

Thermal

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

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
138 W/m·K79.7 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
23 µm/m·K12.8 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
390 J/g168 BTU/lb

Max Service Temperature (continuous)

150°C302 °F
120°C248 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

39 % IACS
33 % IACS

Electrical Resistivity

4.4×10⁻⁸ Ω·m1.73 µΩ·in
5.2×10⁻⁸ Ω·m2.05 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.83 V
-0.7 V

Corrosion Resistance

62 / 100
35 / 100

Manufacturability

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

Machinability

70 / 100
80 / 100

Machinability Rating (AISI 1212 = 100 %)

120%
190%

Weldability

78 / 100
25 / 100

Castability

95 / 100
45 / 100

Brazeability / Solderability

30 / 100
20 / 100

Same in both: Formability (cold) 10 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

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

Typical Recycled Content

60%
25%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12.5 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

98 kN·m/kg
77 kN·m/kg

Specific Stiffness (E / density)

27.1 MN·m/kg
25 MN·m/kg

Modulus of Resilience

239 kJ/m³
86 kJ/m³

Thermal Diffusivity

58.7 mm²/s
51.2 mm²/s

Thermal Shock Resistance Index

25
18

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 scale356ZL203

Manufacturing and finishing

Capability356ZL203
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 ZL203 — frequently asked

Is 356 stronger than ZL203?

Yes. 356 has a typical yield strength of 186 MPa (27 ksi) against 110 MPa (16 ksi) for ZL203 — about 69% more. Tensile strength is 262 MPa (38 ksi) vs 215 MPa (31.2 ksi).

Which is cheaper, 356 or ZL203?

356 is the lower-cost material: it sits in the budget tier ($) while ZL203 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 ZL203?

ZL203, by a small margin. Both rate very good for machinability — 80/100 against 70/100 for 356; for welding the order is 356 first (very good, 78/100) then ZL203 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 356 and ZL203 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.