Aluminum 238.0 vs 355
Aluminum · grade comparison
Aluminum 238.0 and 355 are both aluminum grades. 355 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 165 MPa (23.9 ksi) for 238.0, about 9% more; tensile strength follows at 250 MPa (36.3 ksi) vs 207 MPa (30 ksi). 355 is the more ductile: elongation 3% versus 1.5% for 238.0, and 238.0 is harder (100 HB vs 85 HB). 355 is lighter (2.71 g/cm³ vs 2.95 g/cm³ for 238.0) and 238.0 runs hotter in service (200°C vs 175°C continuous). On the shop floor, 238.0 machines more easily (very good vs good), 355 welds better (good vs poor), and 355 sits in a lower cost tier (budget, $) than 238.0 (standard, $$).
238.0Choose it when the part sees heat, or when the part is machined in volume.
355Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.
238.0 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
Shear Strength
Fatigue Strength (Endurance Limit)
Hardness, Brinell
Fracture Toughness (K_IC)
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
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
Machinability Rating (AISI 1212 = 100 %)
Weldability
Castability
Brazeability / Solderability
Same in both: Formability (cold) 5 / 100 · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg · Embodied Water 1,100 L/kg132 gal/lb · Typical Recycled Content 80%
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 | 238.0 | 355 |
|---|---|---|
| CNC machining | — | Yes |
| Default condition | — | — |
| Relative cost | $$ Standard | $ 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.
238.0 vs 355 — frequently asked
Is 355 stronger than 238.0?
Yes. 355 has a typical yield strength of 180 MPa (26.1 ksi) against 165 MPa (23.9 ksi) for 238.0 — about 9% more. Tensile strength is 250 MPa (36.3 ksi) vs 207 MPa (30 ksi).
Which is cheaper, 238.0 or 355?
355 is the lower-cost material: it sits in the budget tier ($) while 238.0 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, 238.0 or 355?
238.0. Its machinability rates very good (72/100) against good (62/100) for 355; for welding the order is 355 first (good, 55/100) then 238.0 (poor, 22/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 238.0 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.