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Aluminum 2117 vs 7040

Aluminum · grade comparison

Aluminum 2117 and 7040 are both aluminum grades, both aerospace al. 7040 is the stronger of the two: yield strength 450 MPa (65.3 ksi) against 165 MPa (23.9 ksi) for 2117, about 173% more; tensile strength follows at 505 MPa (73.2 ksi) vs 295 MPa (42.8 ksi). In exchange, 2117 is the more ductile: elongation 27% versus 10% for 7040, and 7040 is harder (145 HB vs 70 HB).

2117Choose it when the part is bent, formed or impact-loaded.

7040Choose it when strength drives the design.

2117 vs 7040: properties

21177040

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70.3 GPa10.2 Msi
71 GPa10.3 Msi

Shear Modulus

26.5 GPa3.8 Msi
26.9 GPa3.9 Msi

Bulk Modulus

74 GPa10.7 Msi
75 GPa10.9 Msi

Tensile Strength (Ultimate)

295 MPa42.8 ksi
505 MPa73.2 ksi

Yield Strength (0.2% offset)

165 MPa23.9 ksi
450 MPa65.3 ksi

Elongation at Break

27%
10%

Shear Strength

195 MPa28.3 ksi
300 MPa43.5 ksi

Fatigue Strength (Endurance Limit)

95 MPa13.8 ksi
160 MPa23.2 ksi

Hardness, Brinell

70 HB
145 HB

Compressive Strength

—
465 MPa67.4 ksi

Fracture Toughness (K_IC)

—
38 MPa·√m34.6 ksi·√in

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

554°C1,029 °F
480°C896 °F

Liquidus Temperature

650°C1,202 °F
635°C1,175 °F

Thermal

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

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
154 W/m·K89 BTU/hr·ft·°F

Specific Heat Capacity

864 J/kg·K0.21 BTU/lb·°F
860 J/kg·K0.21 BTU/lb·°F

Thermal Expansion (CTE, 20–100 °C)

23.8 µm/m·K13.2 µin/in·°F
23.4 µm/m·K13 µin/in·°F

Min Service Temperature

-200°C-328 °F
-196°C-321 °F

Same in both: Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 120°C248 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

40 % IACS
40.5 % IACS

Electrical Resistivity

4.31×10⁻⁸ Ω·m1.7 µΩ·in
4.26×10⁻⁸ Ω·m1.68 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.64 V
-0.84 V

Corrosion Resistance

35 / 100
45 / 100

Manufacturability

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

Machinability

65 / 100
70 / 100

Formability (cold)

75 / 100
25 / 100

Brazeability / Solderability

15 / 100
10 / 100

Polishability

55 / 100
60 / 100

Machinability Rating (AISI 1212 = 100 %)

—
90%

Same in both: Weldability 20 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Energy (primary production)

155 MJ/kg66,638 BTU/lb
205 MJ/kg88,134 BTU/lb

Embodied Carbon (primary production)

12 kg CO₂/kg
12.5 kg CO₂/kg

Typical Recycled Content

25%
10%

Same in both: Embodied Water 1,200 L/kg144 gal/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

107 kN·m/kg
179 kN·m/kg

Specific Stiffness (E / density)

25.6 MN·m/kg
25.2 MN·m/kg

Modulus of Resilience

194 kJ/m³
1,426 kJ/m³

Thermal Diffusivity

63.6 mm²/s
63.5 mm²/s

Thermal Shock Resistance Index

27
47

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 scale21177040

Manufacturing and finishing

Capability21177040
Default condition——
Relative cost$$$ Premium$$$ Premium
Min. machined wall0.5 mm0.5 mm
Best machined surfaceRa 0.8 µmRa 0.8 µm

Both are offered for CNC machining and Sheet metal. 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.

2117 vs 7040 — frequently asked

Is 7040 stronger than 2117?

Yes. 7040 has a typical yield strength of 450 MPa (65.3 ksi) against 165 MPa (23.9 ksi) for 2117 — about 173% more. Tensile strength is 505 MPa (73.2 ksi) vs 295 MPa (42.8 ksi).

Which is cheaper, 2117 or 7040?

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

Which is easier to machine, 2117 or 7040?

7040. Its machinability rates very good (70/100) against good (65/100) for 2117.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 2117 and 7040 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.