Aluminum 355 vs LM9
Aluminum · grade comparison
Aluminum 355 and LM9 are both aluminum grades. 355 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 95 MPa (13.8 ksi) for LM9, about 89% more; tensile strength follows at 250 MPa (36.3 ksi) vs 190 MPa (27.6 ksi). 355 is harder — 85 HB against 60 HB for LM9 — which matters for wear surfaces and threads. 355 runs hotter in service (175°C vs 150°C continuous) and 355 conducts electricity better (36 % IACS vs 25 % IACS). On the shop floor, 355 machines more easily (good vs fair), LM9 welds better (very good vs good), and 355 sits in a lower cost tier (budget, $) than LM9 (standard, $$).
355Choose it when strength drives the design, or when surface hardness matters.
LM9Choose it when it will be welded.
355 vs LM9: 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.
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Shear Strength
Fatigue Strength (Endurance Limit)
Fracture Toughness (K_IC)
Hardness, Brinell
Charpy V-Notch Impact (RT)
Hardness, Vickers
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
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)
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
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
Weldability
Formability (cold)
Castability
Brazeability / Solderability
Same in both: Machinability Rating (AISI 1212 = 100 %) 60% · Polishability 45 / 100
Sustainability
Primary-production footprint per kilogram.
Embodied Water
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)
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 | LM9 |
|---|---|---|
| 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 LM9 — frequently asked
Is 355 stronger than LM9?
Yes. 355 has a typical yield strength of 180 MPa (26.1 ksi) against 95 MPa (13.8 ksi) for LM9 — about 89% more. Tensile strength is 250 MPa (36.3 ksi) vs 190 MPa (27.6 ksi).
Which is cheaper, 355 or LM9?
355 is the lower-cost material: it sits in the budget tier ($) while LM9 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 LM9?
355. Its machinability rates good (62/100) against fair (45/100) for LM9; for welding the order is LM9 first (very good, 72/100) then 355 (good, 55/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in 355 and LM9 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.