Aluminum 3005 vs 3A21
Aluminum · grade comparison
Aluminum 3005 and 3A21 are both aluminum grades. 3005 is the stronger of the two: yield strength 155 MPa (22.5 ksi) against 145 MPa (21 ksi) for 3A21, about 7% more; tensile strength follows at 175 MPa (25.4 ksi) vs 150 MPa (21.8 ksi). In exchange, 3A21 is the more ductile: elongation 8% versus 5% for 3005, and 3005 is harder (48 HB vs 40 HB). 3A21 runs hotter in service (150°C vs 120°C continuous). On the shop floor, 3005 sits in a lower cost tier (budget, $) than 3A21 (standard, $$).
3005Choose it when strength drives the design, or when cost is the deciding factor.
3A21Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
3005 vs 3A21: 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.
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Same in both: Elastic (Young's) Modulus 69 GPa10 Msi · Poisson's Ratio 0.33
Physical
Density and transition temperatures.
Melting Point (Solidus)
Liquidus Temperature
Same in both: Density 2.73 g/cm³0.1 lb/in³
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 893 J/kg·K0.21 BTU/lb·°F
Electrical
Conductivity and insulation.
Same in both: Electrical Conductivity 41 % IACS · Electrical Resistivity 4.2×10⁻⁸ Ω·m1.65 µΩ·in
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
Weldability
Brazeability / Solderability
Same in both: Machinability Rating (AISI 1212 = 100 %) 30% · Formability (cold) 70 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Carbon (primary production)
Embodied Water
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Typical Recycled Content 35%
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Modulus of Resilience
Thermal Diffusivity
Thermal Shock Resistance Index
Same in both: Specific Stiffness (E / density) 25.3 MN·m/kg
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 | 3005 | 3A21 |
|---|---|---|
| Sheet metal | Yes | — |
| Default condition | — | — |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | — | — |
| Best machined surface | — | — |
| Anodizing Type II | Yes | — |
| Cerakote | Yes | — |
| Chem Film (Alodine) | Yes | — |
| E-Coating | Yes | — |
| Electropolishing | Yes | — |
| Hard Anodize Type III w/ PTFE | Yes | — |
| Hard Anodizing Type III | Yes | — |
| Nickel Plating | Yes | — |
| PTFE Coating | Yes | — |
| Painting | Yes | — |
| Powder Coating | Yes | — |
They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.
3005 vs 3A21 — frequently asked
Is 3005 stronger than 3A21?
Yes. 3005 has a typical yield strength of 155 MPa (22.5 ksi) against 145 MPa (21 ksi) for 3A21 — about 7% more. Tensile strength is 175 MPa (25.4 ksi) vs 150 MPa (21.8 ksi).
Which is cheaper, 3005 or 3A21?
3005 is the lower-cost material: it sits in the budget tier ($) while 3A21 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, 3005 or 3A21?
3A21, by a small margin. Both rate fair for machinability — 40/100 against 35/100 for 3005; for welding the order is 3A21 first (excellent, 92/100) then 3005 (excellent, 85/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 3005 and 3A21 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.