Aluminum 2017A vs 2A21
Aluminum · grade comparison
Aluminum 2017A and 2A21 are both aluminum grades. 2017A is the stronger of the two: yield strength 260 MPa (37.7 ksi) against 210 MPa (30.5 ksi) for 2A21, about 24% more; tensile strength follows at 410 MPa (59.5 ksi) vs 350 MPa (50.8 ksi). In exchange, 2A21 is the more ductile: elongation 16% versus 14% for 2017A, and 2017A is harder (110 HB vs 100 HB). 2A21 runs hotter in service (175°C vs 120°C continuous) and 2017A conducts heat better (134 W/m·K vs 116 W/m·K). On the shop floor, 2017A machines more easily (very good vs good) and 2A21 welds better (good vs poor).
2017AChoose it when strength drives the design, or when the part is machined in volume.
2A21Choose it when the part is bent, formed or impact-loaded, or when the part sees heat.
2017A vs 2A21: 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
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, Rockwell B
Hardness, Vickers
Reduction in Area
Same in both: Shear Modulus 27 GPa3.9 Msi · Bulk Modulus 75 GPa10.9 Msi · 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
Max Service Temperature (continuous)
Same in both: 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)
Corrosion Resistance
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Castability
Polishability
Same in both: Formability (cold) 45 / 100 · Brazeability / Solderability 15 / 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 1,100 L/kg132 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 | 2017A | 2A21 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Default condition | — | — |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 0.8 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Anodizing Type II | Yes | — |
| Cerakote | Yes | — |
| Chem Film (Alodine) | Yes | — |
| DLC | 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.
2017A vs 2A21 — frequently asked
Is 2017A stronger than 2A21?
Yes. 2017A has a typical yield strength of 260 MPa (37.7 ksi) against 210 MPa (30.5 ksi) for 2A21 — about 24% more. Tensile strength is 410 MPa (59.5 ksi) vs 350 MPa (50.8 ksi).
Which is cheaper, 2017A or 2A21?
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, 2017A or 2A21?
2017A. Its machinability rates very good (75/100) against good (58/100) for 2A21; for welding the order is 2A21 first (good, 60/100) then 2017A (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2017A and 2A21 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.