Aluminum 2117 vs AlSi7Mg
Aluminum · grade comparison
Aluminum 2117 and AlSi7Mg are both aluminum grades, both aerospace al. AlSi7Mg is the stronger of the two: yield strength 240 MPa (34.8 ksi) against 165 MPa (23.9 ksi) for 2117, about 45% more; tensile strength follows at 350 MPa (50.8 ksi) vs 295 MPa (42.8 ksi). In exchange, 2117 is the more ductile: elongation 27% versus 8% for AlSi7Mg, and AlSi7Mg is harder (105 HB vs 70 HB). 2117 conducts heat better (151 W/m·K vs 130 W/m·K). On the shop floor, AlSi7Mg welds better (very good vs poor).
2117Choose it when the part is bent, formed or impact-loaded.
AlSi7MgChoose it when strength drives the design, or when it will be welded.
2117 vs AlSi7Mg: 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
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Elongation at Break
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Compressive Strength
Fracture Toughness (K_IC)
Charpy V-Notch Impact (RT)
Hardness, Vickers
Same in both: Shear Modulus 26.5 GPa3.8 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
Min Service Temperature
Same in both: Max Service Temperature (continuous) 120°C248 °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
Weldability
Formability (cold)
Brazeability / Solderability
Polishability
Machinability Rating (AISI 1212 = 100 %)
Castability
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: 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 | 2117 | AlSi7Mg |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| 3D printing | — | Yes |
| Default condition | — | As Printed |
| Relative cost | $$$ Premium | $$$ Premium |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Anodized (Aluminum AM) | — | Yes |
| 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 | — |
| Plated (Metal AM) | — | Yes |
| Powder Coating | Yes | — |
They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.
2117 vs AlSi7Mg — frequently asked
Is AlSi7Mg stronger than 2117?
Yes. AlSi7Mg has a typical yield strength of 240 MPa (34.8 ksi) against 165 MPa (23.9 ksi) for 2117 — about 45% more. Tensile strength is 350 MPa (50.8 ksi) vs 295 MPa (42.8 ksi).
Which is cheaper, 2117 or AlSi7Mg?
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, 2117 or AlSi7Mg?
2117, by a small margin. Both rate good for machinability — 65/100 against 58/100 for AlSi7Mg; for welding the order is AlSi7Mg first (very good, 70/100) then 2117 (poor, 20/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 2117 and AlSi7Mg 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.