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Aluminum 7021 vs 7072

Aluminum · grade comparison

Aluminum 7021 and 7072 are both aluminum grades. 7021 is the stronger of the two: yield strength 370 MPa (53.7 ksi) against 21 MPa (3.05 ksi) for 7072, about 18 times as much; tensile strength follows at 415 MPa (60.2 ksi) vs 55 MPa (7.98 ksi). In exchange, 7072 is the more ductile: elongation 32% versus 12% for 7021, and 7021 is harder (125 HB vs 20 HB). 7072 runs hotter in service (150°C vs 120°C continuous) and 7072 conducts heat better (227 W/m·K vs 140 W/m·K). On the shop floor, 7021 machines more easily (good vs poor), 7072 welds better (80 vs 70 out of 100), and 7072 sits in a lower cost tier (budget, $) than 7021 (standard, $$).

7021Choose it when strength drives the design, or when the part is machined in volume.

7072Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.

7021 vs 7072: properties

70217072

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

70 GPa10.2 Msi
69 GPa10 Msi

Shear Modulus

26.5 GPa3.8 Msi
26 GPa3.8 Msi

Bulk Modulus

75 GPa10.9 Msi
69 GPa10 Msi

Tensile Strength (Ultimate)

415 MPa60.2 ksi
55 MPa8 ksi

Yield Strength (0.2% offset)

370 MPa53.7 ksi
21 MPa3 ksi

Elongation at Break

12%
32%

Compressive Strength

375 MPa54.4 ksi
—

Shear Strength

250 MPa36.3 ksi
41 MPa5.9 ksi

Fatigue Strength (Endurance Limit)

130 MPa18.9 ksi
30 MPa4.4 ksi

Fracture Toughness (K_IC)

30 MPa·√m27.3 ksi·√in
—

Hardness, Brinell

125 HB
20 HB

Hardness, Vickers

135 HV
—

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.78 g/cm³0.1 lb/in³
2.72 g/cm³0.1 lb/in³

Melting Point (Solidus)

600°C1,112 °F
640°C1,184 °F

Liquidus Temperature

645°C1,193 °F
657°C1,215 °F

Thermal

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

Thermal Conductivity

140 W/m·K80.9 BTU/hr·ft·°F
227 W/m·K131 BTU/hr·ft·°F

Specific Heat Capacity

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

Thermal Expansion (CTE, 20–100 °C)

23.4 µm/m·K13 µin/in·°F
23.6 µm/m·K13.1 µin/in·°F

Latent Heat of Fusion

390 J/g168 BTU/lb
395 J/g170 BTU/lb

Max Service Temperature (continuous)

120°C248 °F
150°C302 °F

Same in both: Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

33 % IACS
60 % IACS

Electrical Resistivity

5.2×10⁻⁸ Ω·m2.05 µΩ·in
2.87×10⁻⁸ Ω·m1.13 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.85 V
-0.96 V

Corrosion Resistance

45 / 100
72 / 100

Manufacturability

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

Machinability

62 / 100
30 / 100

Machinability Rating (AISI 1212 = 100 %)

70%
30%

Weldability

70 / 100
80 / 100

Formability (cold)

35 / 100
95 / 100

Brazeability / Solderability

20 / 100
80 / 100

Polishability

60 / 100
45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12.5 kg CO₂/kg
13 kg CO₂/kg

Typical Recycled Content

25%
20%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

149 kN·m/kg
20 kN·m/kg

Specific Stiffness (E / density)

25.2 MN·m/kg
25.4 MN·m/kg

Modulus of Resilience

978 kJ/m³
3 kJ/m³

Thermal Diffusivity

57.2 mm²/s
92.7 mm²/s

Thermal Shock Resistance Index

35
8

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 scale70727021

Manufacturing and finishing

Capability70217072
CNC machiningYes—
Default condition——
Relative cost$$ Standard$ Budget
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
DLCYes—

Both are offered for Sheet metal. They share 15 finishes: Anodizing Type II, Cerakote, Chem Film (Alodine), E-Coating, Electroless Nickel (EN), Electropolishing, Epoxy Coating, Gold Plating, Hard Anodize Type III w/ PTFE, Hard Anodizing Type III, Nickel Plating, PTFE Coating and 3 more.

7021 vs 7072 — frequently asked

Is 7021 stronger than 7072?

Yes. 7021 has a typical yield strength of 370 MPa (53.7 ksi) against 21 MPa (3.05 ksi) for 7072 — about 18 times as much. Tensile strength is 415 MPa (60.2 ksi) vs 55 MPa (7.98 ksi).

Which is cheaper, 7021 or 7072?

7072 is the lower-cost material: it sits in the budget tier ($) while 7021 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, 7021 or 7072?

7021. Its machinability rates good (62/100) against poor (30/100) for 7072; for welding the order is 7072 first (very good, 80/100) then 7021 (very good, 70/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 7021 and 7072 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.