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Aluminum 355 vs ZL104

Aluminum · grade comparison

Aluminum 355 and ZL104 are both aluminum grades. ZL104 is the stronger of the two: yield strength 200 MPa (29 ksi) against 180 MPa (26.1 ksi) for 355, about 11% more. 355 is harder — 85 HB against 75 HB for ZL104 — which matters for wear surfaces and threads. 355 runs hotter in service (175°C vs 150°C continuous). On the shop floor, ZL104 welds better (very good vs good) and 355 sits in a lower cost tier (budget, $) than ZL104 (standard, $$).

355Choose it when surface hardness matters, or when the part sees heat.

ZL104Choose it when strength drives the design, or when it will be welded.

355 vs ZL104: properties

355ZL104

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Bulk Modulus

69 GPa10 Msi
70 GPa10.2 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
260 MPa37.7 ksi

Yield Strength (0.2% offset)

180 MPa26.1 ksi
200 MPa29 ksi

Shear Strength

195 MPa28.3 ksi
175 MPa25.4 ksi

Fatigue Strength (Endurance Limit)

62 MPa9 ksi
75 MPa10.9 ksi

Fracture Toughness (K_IC)

20 MPa·√m18.2 ksi·√in
19 MPa·√m17.3 ksi·√in

Hardness, Brinell

85 HB
75 HB

Charpy V-Notch Impact (RT)

—
6 J4.4 ft·lbf

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

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

546°C1,015 °F
557°C1,035 °F

Liquidus Temperature

621°C1,150 °F
596°C1,105 °F

Thermal

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

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
145 W/m·K83.8 BTU/hr·ft·°F

Thermal Expansion (CTE, 20–100 °C)

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

Latent Heat of Fusion

389 J/g167 BTU/lb
400 J/g172 BTU/lb

Max Service Temperature (continuous)

175°C347 °F
150°C302 °F

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

Electrical

Conductivity and insulation.

Electrical Conductivity

36 % IACS
33 % IACS

Electrical Resistivity

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

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.83 V

Corrosion Resistance

45 / 100
58 / 100

Manufacturability

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

Machinability

62 / 100
55 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
90%

Weldability

55 / 100
70 / 100

Formability (cold)

5 / 100
10 / 100

Castability

85 / 100
90 / 100

Same in both: Brazeability / Solderability 25 / 100 · Polishability 45 / 100

Sustainability

Primary-production footprint per kilogram.

Embodied Carbon (primary production)

12 kg CO₂/kg
12.5 kg CO₂/kg

Embodied Water

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

Typical Recycled Content

80%
70%

Same in both: Embodied Energy (primary production) 200 MJ/kg85,985 BTU/lb

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

92 kN·m/kg
98 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

228 kJ/m³
282 kJ/m³

Thermal Diffusivity

57.9 mm²/s
56.8 mm²/s

Thermal Shock Resistance Index

24
25

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 scale355ZL104

Manufacturing and finishing

Capability355ZL104
CNC machiningYes—
Default condition——
Relative cost$ Budget$$ Standard
Min. machined wall0.5 mm—
Best machined surfaceRa 0.8 µm—
Anodizing Type IIYes—
CerakoteYes—
Chem Film (Alodine)Yes—
DLCYes—
E-CoatingYes—
ElectropolishingYes—
Hard Anodize Type III w/ PTFEYes—
Hard Anodizing Type IIIYes—
Nickel PlatingYes—
PTFE CoatingYes—
PaintingYes—
Powder CoatingYes—

They share 4 finishes: Electroless Nickel (EN), Epoxy Coating, Gold Plating, Silver Plating.

355 vs ZL104 — frequently asked

Is ZL104 stronger than 355?

Yes. ZL104 has a typical yield strength of 200 MPa (29 ksi) against 180 MPa (26.1 ksi) for 355 — about 11% more. Tensile strength is 260 MPa (37.7 ksi) vs 250 MPa (36.3 ksi).

Which is cheaper, 355 or ZL104?

355 is the lower-cost material: it sits in the budget tier ($) while ZL104 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, 355 or ZL104?

355, by a small margin. Both rate good for machinability — 62/100 against 55/100 for ZL104; for welding the order is ZL104 first (very good, 70/100) then 355 (good, 55/100).

Ready to make it?

Upload a CAD file and FabDigit prices the part in 355 and ZL104 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.