Aluminum 204.0 vs 355
Aluminum · grade comparison
Aluminum 204.0 and 355 are both aluminum grades. 204.0 is the stronger of the two: yield strength 195 MPa (28.3 ksi) against 180 MPa (26.1 ksi) for 355, about 8% more; tensile strength follows at 320 MPa (46.4 ksi) vs 250 MPa (36.3 ksi). 204.0 is the more ductile: elongation 8% versus 3% for 355, and 204.0 is harder (95 HB vs 85 HB). 355 is lighter (2.71 g/cm³ vs 2.8 g/cm³ for 204.0) and 355 runs hotter in service (175°C vs 150°C continuous). On the shop floor, 204.0 machines more easily (excellent vs good), 355 welds better (good vs poor), and 355 sits in a lower cost tier (budget, $) than 204.0 (premium, $$$).
204.0Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
355Choose it when weight is the constraint, or when the part sees heat.
204.0 vs 355: 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)
Elongation at Break
Compressive Strength
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Same in both: 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
Formability (cold)
Castability
Brazeability / Solderability
Polishability
Sustainability
Primary-production footprint per kilogram.
Embodied Water
Typical Recycled Content
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · 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
Same in both: Thermal Shock Resistance Index 24
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 | 204.0 | 355 |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | — |
| Relative cost | $$$ Premium | $ Budget |
| Min. machined wall | — | 0.5 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.
204.0 vs 355 — frequently asked
Is 204.0 stronger than 355?
Yes. 204.0 has a typical yield strength of 195 MPa (28.3 ksi) against 180 MPa (26.1 ksi) for 355 — about 8% more. Tensile strength is 320 MPa (46.4 ksi) vs 250 MPa (36.3 ksi).
Which is cheaper, 204.0 or 355?
355 is the lower-cost material: it sits in the budget tier ($) while 204.0 is premium ($$$). 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, 204.0 or 355?
204.0. Its machinability rates excellent (85/100) against good (62/100) for 355; for welding the order is 355 first (good, 55/100) then 204.0 (poor, 25/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 204.0 and 355 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.