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Aluminum 319 vs 384

Aluminum · grade comparison

Aluminum 319 and 384 are both aluminum grades, both cast al. 384 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 330 MPa (47.9 ksi) vs 186 MPa (27 ksi). 384 is the more ductile: elongation 2.5% versus 2% for 319, and 384 is harder (85 HB vs 70 HB). 319 runs hotter in service (200°C vs 175°C continuous) and 319 conducts heat better (109 W/m·K vs 96 W/m·K). On the shop floor, 319 machines more easily (very good vs good) and 319 welds better (good vs poor).

319Choose it when the part sees heat, or when the part is machined in volume.

384Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

319 vs 384: properties

319384

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

74 GPa10.7 Msi
71 GPa10.3 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
330 MPa47.9 ksi

Yield Strength (0.2% offset)

124 MPa18 ksi
165 MPa23.9 ksi

Elongation at Break

2%
2.5%

Shear Strength

150 MPa21.8 ksi
200 MPa29 ksi

Fatigue Strength (Endurance Limit)

69 MPa10 ksi
140 MPa20.3 ksi

Fracture Toughness (K_IC)

19 MPa·√m17.3 ksi·√in
17 MPa·√m15.5 ksi·√in

Charpy V-Notch Impact (RT)

4 J3 ft·lbf
3 J2.2 ft·lbf

Hardness, Brinell

70 HB
85 HB

Compressive Strength

—
170 MPa24.7 ksi

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

521°C970 °F
482°C900 °F

Liquidus Temperature

604°C1,119 °F
580°C1,076 °F

Thermal

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

Thermal Conductivity

109 W/m·K63 BTU/hr·ft·°F
96 W/m·K55.5 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
21 µm/m·K11.7 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
175°C347 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb

Electrical

Conductivity and insulation.

Electrical Conductivity

27 % IACS
23 % IACS

Electrical Resistivity

6.4×10⁻⁸ Ω·m2.52 µΩ·in
7.5×10⁻⁸ Ω·m2.95 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Corrosion Resistance

35 / 100
38 / 100

Same in both: Galvanic Potential (seawater, vs SCE) -0.78 V

Manufacturability

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

Machinability

72 / 100
60 / 100

Weldability

55 / 100
25 / 100

Castability

90 / 100
95 / 100

Brazeability / Solderability

25 / 100
20 / 100

Same in both: Machinability Rating (AISI 1212 = 100 %) 130% · Formability (cold) 5 / 100 · Polishability 40 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
205 MJ/kg88,134 BTU/lb

Embodied Water

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

Typical Recycled Content

75%
95%

Same in both: Embodied Carbon (primary production) 12 kg CO₂/kg

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

67 kN·m/kg
117 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
25.2 MN·m/kg

Modulus of Resilience

104 kJ/m³
192 kJ/m³

Thermal Diffusivity

40.6 mm²/s
35.4 mm²/s

Thermal Shock Resistance Index

13
21

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 scale319384

Manufacturing and finishing

Capability319384
Default condition——
Relative cost$ Budget$ Budget
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 384 — frequently asked

Is 384 stronger than 319?

Yes. 384 has a typical yield strength of 165 MPa (23.9 ksi) against 124 MPa (18 ksi) for 319 — about 33% more. Tensile strength is 330 MPa (47.9 ksi) vs 186 MPa (27 ksi).

Which is cheaper, 319 or 384?

Both sit in the same relative cost tier ($, budget); the part price will be decided by machining time, tolerance and quantity rather than by the material.

Which is easier to machine, 319 or 384?

319. Its machinability rates very good (72/100) against good (60/100) for 384; for welding the order is 319 first (good, 55/100) then 384 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 319 and 384 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.