Aluminum 7005 vs 7021
Aluminum · grade comparison
Aluminum 7005 and 7021 are both aluminum grades, both high strength al. 7021 is the stronger of the two: yield strength 370 MPa (53.7 ksi) against 295 MPa (42.8 ksi) for 7005, about 25% more; tensile strength follows at 415 MPa (60.2 ksi) vs 350 MPa (50.8 ksi). 7021 is harder — 125 HB against 94 HB for 7005 — which matters for wear surfaces and threads. 7005 conducts electricity better (40 % IACS vs 33 % IACS). On the shop floor, 7005 welds better (80 vs 70 out of 100).
7005Choose it when it will be welded.
7021Choose it when strength drives the design, or when surface hardness matters.
7005 vs 7021: 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)
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Hardness, Vickers
Same in both: Poisson's Ratio 0.33 · Elongation at Break 12% · Fracture Toughness (K_IC) 30 MPa·√m27.3 ksi·√in
Physical
Density and transition temperatures.
Melting Point (Solidus)
Same in both: Density 2.78 g/cm³0.1 lb/in³ · Liquidus Temperature 645°C1,193 °F
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Same in both: Latent Heat of Fusion 390 J/g168 BTU/lb · Max Service Temperature (continuous) 120°C248 °F · Min Service Temperature -196°C-321 °F
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Galvanic Potential (seawater, vs SCE)
Same in both: Corrosion Resistance 45 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Castability
Polishability
Same in both: Machinability Rating (AISI 1212 = 100 %) 70% · Formability (cold) 35 / 100 · Brazeability / Solderability 20 / 100
Sustainability
Primary-production footprint per kilogram.
Typical Recycled Content
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · 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 | 7005 | 7021 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.5 mm | 0.5 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.
7005 vs 7021 — frequently asked
Is 7021 stronger than 7005?
Yes. 7021 has a typical yield strength of 370 MPa (53.7 ksi) against 295 MPa (42.8 ksi) for 7005 — about 25% more. Tensile strength is 415 MPa (60.2 ksi) vs 350 MPa (50.8 ksi).
Which is cheaper, 7005 or 7021?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which welds better, 7005 or 7021?
7005. Its weldability rates very good (80/100) against very good (70/100) for 7021.
Ready to make it?
Upload a CAD file and FabDigit prices the part in 7005 and 7021 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.