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Aluminum 319 vs A356

Aluminum · grade comparison

Aluminum 319 and A356 are both aluminum grades, both cast al. A356 is the stronger of the two: yield strength 165 MPa (23.9 ksi) against 124 MPa (18 ksi) for 319, about 33% more; tensile strength follows at 230 MPa (33.4 ksi) vs 186 MPa (27 ksi). A356 is the more ductile: elongation 4% versus 2% for 319, and A356 is harder (75 HB vs 70 HB). A356 is lighter (2.68 g/cm³ vs 2.79 g/cm³ for 319) and 319 runs hotter in service (200°C vs 150°C continuous). On the shop floor, A356 welds better (very good vs good) and 319 sits in a lower cost tier (budget, $) than A356 (standard, $$).

319Choose it when the part sees heat, or when cost is the deciding factor.

A356Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

319 vs A356: properties

319A356

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
72.4 GPa10.5 Msi

Shear Modulus

27.5 GPa4 Msi
26.5 GPa3.8 Msi

Bulk Modulus

72 GPa10.4 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

186 MPa27 ksi
230 MPa33.4 ksi

Yield Strength (0.2% offset)

124 MPa18 ksi
165 MPa23.9 ksi

Elongation at Break

2%
4%

Shear Strength

150 MPa21.8 ksi
180 MPa26.1 ksi

Fatigue Strength (Endurance Limit)

69 MPa10 ksi
90 MPa13.1 ksi

Fracture Toughness (K_IC)

19 MPa·√m17.3 ksi·√in
20 MPa·√m18.2 ksi·√in

Hardness, Brinell

70 HB
75 HB

Compressive Strength

—
175 MPa25.4 ksi

Hardness, Vickers

—
85 HV

Same in both: Poisson's Ratio 0.33 · Charpy V-Notch Impact (RT) 4 J3 ft·lbf

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

521°C970 °F
557°C1,035 °F

Liquidus Temperature

604°C1,119 °F
613°C1,135 °F

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
151 W/m·K87.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
21.4 µm/m·K11.9 µin/in·°F

Max Service Temperature (continuous)

200°C392 °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

27 % IACS
39 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
4.42×10⁻⁸ Ω·m1.74 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.83 V

Corrosion Resistance

35 / 100
68 / 100

Manufacturability

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

Machinability

72 / 100
68 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
80%

Weldability

55 / 100
80 / 100

Formability (cold)

5 / 100
15 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

25 / 100
40 / 100

Polishability

40 / 100
55 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

1,200 L/kg144 gal/lb
1,150 L/kg138 gal/lb

Typical Recycled Content

75%
50%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

67 kN·m/kg
86 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
27 MN·m/kg

Modulus of Resilience

104 kJ/m³
188 kJ/m³

Thermal Diffusivity

40.6 mm²/s
58.5 mm²/s

Thermal Shock Resistance Index

13
22

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 scale319A356

Manufacturing and finishing

Capability319A356
Casting & forging—Yes
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall0.5 mm1 mm
Best machined surfaceRa 0.8 µmRa 1.6 µm

Both are offered for CNC machining. Both take the same 16 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), DLC, E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating and 4 more.

319 vs A356 — frequently asked

Is A356 stronger than 319?

Yes. A356 has a typical yield strength of 165 MPa (23.9 ksi) against 124 MPa (18 ksi) for 319 — about 33% more. Tensile strength is 230 MPa (33.4 ksi) vs 186 MPa (27 ksi).

Which is cheaper, 319 or A356?

319 is the lower-cost material: it sits in the budget tier ($) while A356 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 welds better, 319 or A356?

A356. Its weldability rates very good (80/100) against good (55/100) for 319.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 319 and A356 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.