Aluminum 355 vs ZL109
Aluminum · grade comparison
Aluminum 355 and ZL109 are both aluminum grades. ZL109 is the stronger of the two: yield strength 225 MPa (32.6 ksi) against 180 MPa (26.1 ksi) for 355, about 25% more; tensile strength follows at 265 MPa (38.4 ksi) vs 250 MPa (36.3 ksi). In exchange, 355 is the more ductile: elongation 3% versus 0.8% for ZL109, and ZL109 is harder (115 HB vs 85 HB). ZL109 is stiffer (80 GPa vs 71 GPa) and ZL109 runs hotter in service (250°C vs 175°C continuous). On the shop floor, 355 machines more easily (good vs fair), 355 welds better (good vs poor), and 355 sits in a lower cost tier (budget, $) than ZL109 (standard, $$).
355Choose it when the part is bent, formed or impact-loaded, or when the part is machined in volume.
ZL109Choose it when strength drives the design, or when the part sees heat.
355 vs ZL109: 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
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Hardness, Vickers
Same in both: Poisson's Ratio 0.33 · Shear Strength 195 MPa28.3 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
Specific Heat Capacity
Thermal Expansion (CTE, 20–100 °C)
Latent Heat of Fusion
Max Service Temperature (continuous)
Min Service Temperature
Electrical
Conductivity and insulation.
Electrical Conductivity
Electrical Resistivity
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: Galvanic Potential (seawater, vs SCE) -0.78 V
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Machinability Rating (AISI 1212 = 100 %)
Weldability
Castability
Brazeability / Solderability
Polishability
Same in both: Formability (cold) 5 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Typical Recycled Content
Same in both: Embodied Water 1,100 L/kg132 gal/lb
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 | 355 | ZL109 |
|---|---|---|
| CNC machining | Yes | — |
| Default condition | — | — |
| Relative cost | $ Budget | $$ Standard |
| 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.
355 vs ZL109 — frequently asked
Is ZL109 stronger than 355?
Yes. ZL109 has a typical yield strength of 225 MPa (32.6 ksi) against 180 MPa (26.1 ksi) for 355 — about 25% more. Tensile strength is 265 MPa (38.4 ksi) vs 250 MPa (36.3 ksi).
Which is cheaper, 355 or ZL109?
355 is the lower-cost material: it sits in the budget tier ($) while ZL109 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 ZL109?
355. Its machinability rates good (62/100) against fair (45/100) for ZL109; for welding the order is 355 first (good, 55/100) then ZL109 (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 355 and ZL109 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.