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Aluminum 319 vs 390

Aluminum · grade comparison

Aluminum 319 and 390 are both aluminum grades, both cast al. 390 is the stronger of the two: yield strength 241 MPa (35 ksi) against 124 MPa (18 ksi) for 319, about 94% more; tensile strength follows at 279 MPa (40.5 ksi) vs 186 MPa (27 ksi). In exchange, 319 is the more ductile: elongation 2% versus 1% for 390, and 390 is harder (120 HB vs 70 HB). 390 is stiffer (81 GPa vs 74 GPa) and 319 runs hotter in service (200°C vs 175°C continuous). On the shop floor, 319 machines more easily (very good vs poor), 319 welds better (good vs poor), and 319 sits in a lower cost tier (budget, $) than 390 (standard, $$).

319Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

390Choose it when strength drives the design.

319 vs 390: properties

319390

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
81 GPa11.7 Msi

Shear Modulus

27.5 GPa4 Msi
30.5 GPa4.4 Msi

Bulk Modulus

72 GPa10.4 Msi
79 GPa11.5 Msi

Tensile Strength (Ultimate)

186 MPa27 ksi
279 MPa40.5 ksi

Yield Strength (0.2% offset)

124 MPa18 ksi
241 MPa35 ksi

Elongation at Break

2%
1%

Shear Strength

150 MPa21.8 ksi
172 MPa24.9 ksi

Fatigue Strength (Endurance Limit)

69 MPa10 ksi
138 MPa20 ksi

Fracture Toughness (K_IC)

19 MPa·√m17.3 ksi·√in
15 MPa·√m13.7 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
2 J1.5 ft·lbf

Hardness, Brinell

70 HB
120 HB

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

521°C970 °F
507°C945 °F

Liquidus Temperature

604°C1,119 °F
649°C1,200 °F

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
134 W/m·K77.4 BTU/hr·ft·°F

Specific Heat Capacity

963 J/kg·K0.23 BTU/lb·°F
880 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
18 µm/m·K10 µin/in·°F

Latent Heat of Fusion

389 J/g167 BTU/lb
480 J/g206 BTU/lb

Max Service Temperature (continuous)

200°C392 °F
175°C347 °F

Min Service Temperature

-196°C-321 °F
-80°C-112 °F

Electrical

Conductivity and insulation.

Same in both: Electrical Conductivity 27 % IACS · Electrical Resistivity 6.4×10⁻⁸ Ω·m2.52 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.75 V

Corrosion Resistance

35 / 100
42 / 100

Manufacturability

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

Machinability

72 / 100
28 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
60%

Weldability

55 / 100
22 / 100

Formability (cold)

5 / 100
3 / 100

Castability

90 / 100
82 / 100

Brazeability / Solderability

25 / 100
20 / 100

Same in both: Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

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

Typical Recycled Content

75%
70%

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
102 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
29.7 MN·m/kg

Modulus of Resilience

104 kJ/m³
359 kJ/m³

Thermal Diffusivity

40.6 mm²/s
55.8 mm²/s

Thermal Shock Resistance Index

13
26

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 scale319390

Manufacturing and finishing

Capability319390
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall0.5 mm0.5 mm
Best machined surfaceRa 0.8 µmRa 0.8 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 390 — frequently asked

Is 390 stronger than 319?

Yes. 390 has a typical yield strength of 241 MPa (35 ksi) against 124 MPa (18 ksi) for 319 — about 94% more. Tensile strength is 279 MPa (40.5 ksi) vs 186 MPa (27 ksi).

Which is cheaper, 319 or 390?

319 is the lower-cost material: it sits in the budget tier ($) while 390 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, 319 or 390?

319. Its machinability rates very good (72/100) against poor (28/100) for 390; for welding the order is 319 first (good, 55/100) then 390 (poor, 22/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 319 and 390 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.