Aluminum 7021 vs 7075
Aluminum · grade comparison
Aluminum 7021 and 7075 are both aluminum grades, both high strength al. 7075 is the stronger of the two: yield strength 503 MPa (73 ksi) against 370 MPa (53.7 ksi) for 7021, about 36% more; tensile strength follows at 572 MPa (83 ksi) vs 415 MPa (60.2 ksi). 7075 is harder — 150 HB against 125 HB for 7021 — which matters for wear surfaces and threads. On the shop floor, 7075 machines more easily (very good vs good), 7021 welds better (very good vs poor), and 7021 forms better (fair vs poor).
7021Choose it when it will be welded, or when cost is the deciding factor.
7075Choose it when strength drives the design, or when surface hardness matters.
7021 vs 7075: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all aluminum grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Vickers
Reduction in Area
Charpy V-Notch Impact (RT)
Hardness, Rockwell B
Same in both: Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Density
Melting Point (Solidus)
Liquidus Temperature
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Same in both: Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Resistivity
Same in both: Electrical Conductivity 33 % IACS
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Formability (cold)
Brazeability / Solderability
Same in both: Polishability 60 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 12.5 kg CO₂/kg · Embodied Water 1,200 L/kg144 gal/lb
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
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.
Manufacturing and finishing
| Capability | 7021 | 7075 |
|---|---|---|
| Default condition | — | T6 |
| Relative cost | $$ Standard | $$$ Premium |
| Min. machined wall | 0.5 mm | 0.8 mm |
| Best machined surface | Ra 0.8 µm | Ra 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.
7021 vs 7075 — frequently asked
Is 7075 stronger than 7021?
Yes. 7075 has a typical yield strength of 503 MPa (73 ksi) against 370 MPa (53.7 ksi) for 7021 — about 36% more. Tensile strength is 572 MPa (83 ksi) vs 415 MPa (60.2 ksi).
Which is cheaper, 7021 or 7075?
7021 is the lower-cost material: it sits in the standard tier ($$) while 7075 is premium ($$$). 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 7075?
7075. Its machinability rates very good (78/100) against good (62/100) for 7021; for welding the order is 7021 first (very good, 70/100) then 7075 (poor, 18/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 7021 and 7075 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.