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Aluminum 355 vs LM27

Aluminum · grade comparison

Aluminum 355 and LM27 are both aluminum grades. 355 is the stronger of the two: yield strength 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for LM27, about 64% more; tensile strength follows at 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi). 355 is the more ductile: elongation 3% versus 2% for LM27, and 355 is harder (85 HB vs 80 HB). 355 runs hotter in service (175°C vs 150°C continuous) and 355 conducts heat better (151 W/m·K vs 109 W/m·K). On the shop floor, 355 welds better (good vs fair) and 355 sits in a lower cost tier (budget, $) than LM27 (standard, $$).

355Choose it when strength drives the design, or when the part is bent, formed or impact-loaded.

355 vs LM27: properties

355LM27

Mechanical

Strength, stiffness, ductility and hardness at room temperature.

Elastic (Young's) Modulus

71 GPa10.3 Msi
74 GPa10.7 Msi

Shear Modulus

26.5 GPa3.8 Msi
27.5 GPa4 Msi

Bulk Modulus

69 GPa10 Msi
71 GPa10.3 Msi

Tensile Strength (Ultimate)

250 MPa36.3 ksi
180 MPa26.1 ksi

Yield Strength (0.2% offset)

180 MPa26.1 ksi
110 MPa16 ksi

Elongation at Break

3%
2%

Shear Strength

195 MPa28.3 ksi
150 MPa21.8 ksi

Fatigue Strength (Endurance Limit)

62 MPa9 ksi
70 MPa10.2 ksi

Fracture Toughness (K_IC)

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

Hardness, Brinell

85 HB
80 HB

Compressive Strength

—
120 MPa17.4 ksi

Charpy V-Notch Impact (RT)

—
3 J2.2 ft·lbf

Hardness, Vickers

—
85 HV

Same in both: Poisson's Ratio 0.33

Physical

Density and transition temperatures.

Density

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

Melting Point (Solidus)

546°C1,015 °F
520°C968 °F

Liquidus Temperature

621°C1,150 °F
604°C1,119 °F

Thermal

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

Thermal Conductivity

151 W/m·K87.2 BTU/hr·ft·°F
109 W/m·K63 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

Max Service Temperature (continuous)

175°C347 °F
150°C302 °F

Min Service Temperature

-196°C-321 °F
-50°C-58 °F

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

36 % IACS
27 % IACS

Electrical Resistivity

4.8×10⁻⁸ Ω·m1.89 µΩ·in
6.4×10⁻⁸ Ω·m2.52 µΩ·in

Chemical & Environmental

Corrosion and environmental resistance (0–100 scores).

Galvanic Potential (seawater, vs SCE)

-0.78 V
-0.8 V

Corrosion Resistance

45 / 100
42 / 100

Manufacturability

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

Machinability

62 / 100
65 / 100

Machinability Rating (AISI 1212 = 100 %)

60%
130%

Weldability

55 / 100
40 / 100

Formability (cold)

5 / 100
—

Brazeability / Solderability

25 / 100
20 / 100

Polishability

45 / 100
40 / 100

Same in both: Castability 85 / 100

Sustainability

Primary-production footprint per kilogram.

Typical Recycled Content

80%
90%

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

Common Calculations

Ratios derived from the values above.

Specific Strength (UTS / density)

92 kN·m/kg
65 kN·m/kg

Specific Stiffness (E / density)

26.2 MN·m/kg
26.8 MN·m/kg

Modulus of Resilience

228 kJ/m³
82 kJ/m³

Thermal Diffusivity

57.9 mm²/s
41 mm²/s

Thermal Shock Resistance Index

24
12

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 scale355LM27

Manufacturing and finishing

Capability355LM27
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 LM27 — frequently asked

Is 355 stronger than LM27?

Yes. 355 has a typical yield strength of 180 MPa (26.1 ksi) against 110 MPa (16 ksi) for LM27 — about 64% more. Tensile strength is 250 MPa (36.3 ksi) vs 180 MPa (26.1 ksi).

Which is cheaper, 355 or LM27?

355 is the lower-cost material: it sits in the budget tier ($) while LM27 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 welds better, 355 or LM27?

355. Its weldability rates good (55/100) against fair (40/100) for LM27.

Ready to make it?

Upload a CAD file and FabDigit prices the part in 355 and LM27 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.