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Aluminum 8006 vs 8091

Aluminum · grade comparison

Aluminum 8006 and 8091 are both aluminum grades. 8091 is the stronger of the two: yield strength 480 MPa (69.6 ksi) against 130 MPa (18.9 ksi) for 8006, about 3.7 times as much; tensile strength follows at 540 MPa (78.3 ksi) vs 155 MPa (22.5 ksi). In exchange, 8006 is the more ductile: elongation 10% versus 5% for 8091, and 8091 is harder (155 HB vs 45 HB). 8091 is lighter (2.55 g/cm³ vs 2.71 g/cm³ for 8006) and 8091 is stiffer (80 GPa vs 69 GPa). On the shop floor, 8091 machines more easily (good vs fair), 8006 welds better (very good vs poor), and 8006 sits in a lower cost tier (budget, $) than 8091 (high, $$$$).

8006Choose it when the part is bent, formed or impact-loaded, or when it will be welded.

8091Choose it when strength drives the design, or when weight is the constraint.

8006 vs 8091: properties

80068091

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

69 GPa10 Msi
80 GPa11.6 Msi

Shear Modulus

26 GPa3.8 Msi
30 GPa4.4 Msi

Bulk Modulus

70 GPa10.2 Msi
76 GPa11 Msi

Poisson's Ratio

0.33
0.34

Tensile Strength (Ultimate)

155 MPa22.5 ksi
540 MPa78.3 ksi

Yield Strength (0.2% offset)

130 MPa18.9 ksi
480 MPa69.6 ksi

Elongation at Break

10%
5%

Shear Strength

95 MPa13.8 ksi
310 MPa45 ksi

Fatigue Strength (Endurance Limit)

55 MPa8 ksi
165 MPa23.9 ksi

Hardness, Brinell

45 HB
155 HB

Compressive Strength

—
495 MPa71.8 ksi

Fracture Toughness (K_IC)

—
28 MPa·√m25.5 ksi·√in

Hardness, Vickers

—
165 HV

Physical

Density and transition temperatures.

Density

2.71 g/cm³0.1 lb/in³
2.55 g/cm³0.09 lb/in³

Melting Point (Solidus)

630°C1,166 °F
570°C1,058 °F

Liquidus Temperature

655°C1,211 °F
650°C1,202 °F

Thermal

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

Thermal Conductivity

185 W/m·K107 BTU/hr·ft·°F
95 W/m·K54.9 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

23.6 µm/m·K13.1 µin/in·°F
21.4 µm/m·K11.9 µin/in·°F

Min Service Temperature

-196°C-321 °F
-253°C-423 °F

Same in both: Specific Heat Capacity 900 J/kg·K0.21 BTU/lb·°F · Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 120°C248 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

47 % IACS
19 % IACS

Electrical Resistivity

3.7×10⁻⁸ Ω·m1.46 µΩ·in
9.1×10⁻⁸ Ω·m3.58 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.73 V

Corrosion Resistance

62 / 100
40 / 100

Manufacturability

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

Machinability

35 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

30%
70%

Weldability

70 / 100
25 / 100

Formability (cold)

78 / 100
30 / 100

Brazeability / Solderability

70 / 100
10 / 100

Polishability

40 / 100
60 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

200 MJ/kg85,985 BTU/lb
260 MJ/kg111,780 BTU/lb

Embodied Carbon (primary production)

12 kg CO₂/kg
18 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

35%
3%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

57 kN·m/kg
212 kN·m/kg

Specific Stiffness (E / density)

25.5 MN·m/kg
31.4 MN·m/kg

Modulus of Resilience

122 kJ/m³
1,440 kJ/m³

Thermal Diffusivity

75.9 mm²/s
41.4 mm²/s

Thermal Shock Resistance Index

18
30

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 scale80068091

Manufacturing and finishing

Capability80068091
Sheet metalYes—
Default condition——
Relative cost$ Budget$$$$ High
Min. machined wall——
Best machined surface——
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
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.

8006 vs 8091 — frequently asked

Is 8091 stronger than 8006?

Yes. 8091 has a typical yield strength of 480 MPa (69.6 ksi) against 130 MPa (18.9 ksi) for 8006 — about 3.7 times as much. Tensile strength is 540 MPa (78.3 ksi) vs 155 MPa (22.5 ksi).

Which is cheaper, 8006 or 8091?

8006 is the lower-cost material: it sits in the budget tier ($) while 8091 is high ($$$$). 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, 8006 or 8091?

8091. Its machinability rates good (65/100) against fair (35/100) for 8006; for welding the order is 8006 first (very good, 70/100) then 8091 (poor, 25/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 8006 and 8091 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.