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Aluminum 308.0 vs 355

Aluminum · grade comparison

Aluminum 308.0 and 355 are both aluminum grades. 355 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for 308.0, about 64% more; tensile strength follows at 250 MPa (36.3 ksi) vs 195 MPa (28.3 ksi). 355 is the more ductile: elongation 3% versus 2% for 308.0, and 355 is harder (85 HB vs 70 HB). 308.0 runs hotter in service (200°C vs 175°C continuous). On the shop floor, 308.0 machines more easily (very good vs good), 355 welds better (good vs poor), and 355 sits in a lower cost tier (budget, $) than 308.0 (standard, $$).

308.0Choose 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.

308.0 vs 355: properties

308.0355

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Tensile Strength (Ultimate)

195 MPa28.3 ksi
250 MPa36.3 ksi

Yield Strength (0.2% offset)

110 MPa16 ksi
180 MPa26.1 ksi

Elongation at Break

2%
3%

Shear Strength

150 MPa21.8 ksi
195 MPa28.3 ksi

Fatigue Strength (Endurance Limit)

90 MPa13.1 ksi
62 MPa9 ksi

Fracture Toughness (K_IC)

17 MPa·√m15.5 ksi·√in
20 MPa·√m18.2 ksi·√in

Charpy V-Notch Impact (RT)

3 J2.2 ft·lbf
—

Hardness, Brinell

70 HB
85 HB

Hardness, Rockwell B

33 HRB
—

Same in both: Elastic (Young's) Modulus 71 GPa10.3 Msi · Shear Modulus 26.5 GPa3.8 Msi · Bulk Modulus 69 GPa10 Msi · Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

2.79 g/cm³0.1 lb/in³
2.71 g/cm³0.1 lb/in³

Melting Point (Solidus)

521°C970 °F
546°C1,015 °F

Liquidus Temperature

616°C1,141 °F
621°C1,150 °F

Thermal

How each material carries heat and how hot it can run.

Thermal Conductivity

142 W/m·K82 BTU/hr·ft·°F
151 W/m·K87.2 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

21.5 µm/m·K11.9 µin/in·°F
22.4 µm/m·K12.4 µin/in·°F

Max Service Temperature (continuous)

200°C392 °F
175°C347 °F

Same in both: Specific Heat Capacity 963 J/kg·K0.23 BTU/lb·°F · Latent Heat of Fusion 389 J/g167 BTU/lb · Min Service Temperature -196°C-321 °F

Electrical

Conductivity and insulation.

Electrical Conductivity

33 % IACS
36 % IACS

Electrical Resistivity

5.2×10⁻⁸ Ω·m2.05 µΩ·in
4.8×10⁻⁸ Ω·m1.89 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.75 V
-0.78 V

Corrosion Resistance

38 / 100
45 / 100

Manufacturability

FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.

Machinability

72 / 100
62 / 100

Machinability Rating (AISI 1212 = 100 %)

150%
60%

Weldability

30 / 100
55 / 100

Brazeability / Solderability

20 / 100
25 / 100

Polishability

40 / 100
45 / 100

Formability (cold)

—
5 / 100

Same in both: Castability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Water

1,200 L/kg144 gal/lb
1,100 L/kg132 gal/lb

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb · Embodied Carbon (primary production) 12 kg CO₂/kg · Typical Recycled Content 80%

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

70 kN·m/kg
92 kN·m/kg

Specific Stiffness (E / density)

25.4 MN·m/kg
26.2 MN·m/kg

Modulus of Resilience

85 kJ/m³
228 kJ/m³

Thermal Diffusivity

52.9 mm²/s
57.9 mm²/s

Thermal Shock Resistance Index

18
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.

20501002005002.22.42.62.83Density (g/cm³)Yield strength (MPa) — log scale355308.0

Manufacturing and finishing

Capability308.0355
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.

308.0 vs 355 — frequently asked

Is 355 stronger than 308.0?

Yes. 355 has a typical yield strength of 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for 308.0 — about 64% more. Tensile strength is 250 MPa (36.3 ksi) vs 195 MPa (28.3 ksi).

Which is cheaper, 308.0 or 355?

355 is the lower-cost material: it sits in the budget tier ($) while 308.0 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, 308.0 or 355?

308.0. Its machinability rates very good (72/100) against good (62/100) for 355; for welding the order is 355 first (good, 55/100) then 308.0 (poor, 30/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 308.0 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.