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Aluminum 319 vs AL9

Aluminum · grade comparison

Aluminum 319 and AL9 are both aluminum grades. AL9 is the stronger of the two: yield strength 185 MPa (26.8 ksi) against 124 MPa (18 ksi) for 319, about 49% more; tensile strength follows at 240 MPa (34.8 ksi) vs 186 MPa (27 ksi). AL9 is the more ductile: elongation 4% versus 2% for 319, and AL9 is harder (80 HB vs 70 HB). AL9 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, 319 machines more easily (very good vs good), AL9 welds better (very good vs good), and 319 sits in a lower cost tier (budget, $) than AL9 (standard, $$).

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

AL9Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

319 vs AL9: properties

319AL9

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
27 GPa3.9 Msi

Bulk Modulus

72 GPa10.4 Msi
75 GPa10.9 Msi

Tensile Strength (Ultimate)

186 MPa27 ksi
240 MPa34.8 ksi

Yield Strength (0.2% offset)

124 MPa18 ksi
185 MPa26.8 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
80 HB

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

Max Service Temperature (continuous)

200°C392 °F
150°C302 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 21.5 µm/m·K11.9 µin/in·°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
4.4×10⁻⁸ Ω·m1.73 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
58 / 100

Manufacturability

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

Machinability

72 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

130%
60%

Weldability

55 / 100
80 / 100

Formability (cold)

5 / 100
10 / 100

Castability

90 / 100
92 / 100

Brazeability / Solderability

25 / 100
35 / 100

Polishability

40 / 100
50 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

75%
60%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

67 kN·m/kg
90 kN·m/kg

Specific Stiffness (E / density)

26.5 MN·m/kg
27 MN·m/kg

Modulus of Resilience

104 kJ/m³
236 kJ/m³

Thermal Diffusivity

40.6 mm²/s
58.5 mm²/s

Thermal Shock Resistance Index

13
23

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 scale319AL9

Manufacturing and finishing

Capability319AL9
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.

319 vs AL9 — frequently asked

Is AL9 stronger than 319?

Yes. AL9 has a typical yield strength of 185 MPa (26.8 ksi) against 124 MPa (18 ksi) for 319 — about 49% more. Tensile strength is 240 MPa (34.8 ksi) vs 186 MPa (27 ksi).

Which is cheaper, 319 or AL9?

319 is the lower-cost material: it sits in the budget tier ($) while AL9 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 AL9?

319. Its machinability rates very good (72/100) against good (60/100) for AL9; for welding the order is AL9 first (very good, 80/100) then 319 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 319 and AL9 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.