Aluminum 357 vs 384
Aluminum · grade comparison
Aluminum 357 and 384 are both aluminum grades, both cast al. 357 is the stronger of the two: yield strength 275 MPa (39.9 ksi) against 165 MPa (23.9 ksi) for 384, about 67% more. 357 is the more ductile: elongation 5% versus 2.5% for 384, and 357 is harder (90 HB vs 85 HB). 357 is lighter (2.68 g/cm³ vs 2.82 g/cm³ for 384) and 384 runs hotter in service (175°C vs 150°C continuous). On the shop floor, 357 welds better (excellent vs poor) and 384 sits in a lower cost tier (budget, $) than 357 (standard, $$).
357Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
384Choose it when the part sees heat, or when cost is the deciding factor.
357 vs 384: 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
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Charpy V-Notch Impact (RT)
Same in both: Bulk Modulus 70 GPa10.2 Msi · Poisson's Ratio 0.33 · Tensile Strength (Ultimate) 330 MPa47.9 ksi
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
Thermal Expansion (CTE, 20–100 °C)
Max Service Temperature (continuous)
Min Service Temperature
Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb
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)
Castability
Brazeability / Solderability
Polishability
Machinability Rating (AISI 1212 = 100 %)
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Water
Typical Recycled Content
Same in both: Embodied Carbon (primary production) 12 kg CO₂/kg
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 | 357 | 384 |
|---|---|---|
| Default condition | — | — |
| Relative cost | $$ Standard | $ Budget |
| 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. 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.
357 vs 384 — frequently asked
Is 357 stronger than 384?
Yes. 357 has a typical yield strength of 275 MPa (39.9 ksi) against 165 MPa (23.9 ksi) for 384 — about 67% more. Tensile strength is 330 MPa (47.9 ksi) vs 330 MPa (47.9 ksi).
Which is cheaper, 357 or 384?
384 is the lower-cost material: it sits in the budget tier ($) while 357 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, 357 or 384?
357, by a small margin. Both rate good for machinability — 65/100 against 60/100 for 384; for welding the order is 357 first (excellent, 85/100) then 384 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 357 and 384 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.