Materials / Compare

Aluminum 6061-T6 vs. Plastic Polycarbonate

Compare Aluminum 6061-T6 vs. Plastic Polycarbonate strength, stiffness, weight and thermal properties.

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Aluminum 6061-T6Wrought
Plastic PolycarbonateBulk polymer (molded or machined)
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Mechanical
Yield strength276MPasourcetypical, 0.2% offset, .500 in dia specimen65MPasourcetypical, tensile yield
Ultimate tensile strength310MPasourcetypical65MPasourcetypical, stress at break
Flexural strengthnot sourced97MPasourcetypical, flexural strength
Elongation at break17%sourcetypical, in 4D, 0.500 in dia specimen125%sourcetypical, strain at break
Young's modulus (stiffness)68.3GPasourcetypical28.5x stiffer2.4GPasourcetypical
Density2,700kg/m³sourcenominal1,200kg/m³sourcetypical
Strength to weight102kN·m/kg1.89x higher54.2kN·m/kg
Stiffness to weight25.3MN·m/kg12.6x higher2MN·m/kg
Poisson's ratio0.33sourcetypical (handbook physical constant)0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus25.7GPa29.5x stiffer in shear0.87GPa
Bulk modulus67GPa3.33GPa
Speed of sound5,030m/s1,414m/s
Thermal
Thermal conductivity167W/m·Ksourcetypical, 20 °C0.2W/m·Ksourcetypical, through-plane, 23 C
Thermal expansion23.6µm/m·Ksourcetypical, mean 20-100 °C65µm/m·Ksourcetypical, 23-55 C, parallel and normal
100 mm part over a 50 °C swing118µm growth2.75x less325µm growth
Specific heat896J/kg·Ksourcetypical, at 100 °C1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766
Heats up and cools (diffusivity)69mm²/s485x faster0.142mm²/s
Thermal shock resistance19,159W/m371x more resistant51.7W/m
Melting point582–652°Csourcesolidus-liquidusnot sourced
Glass transitionnot sourced144°Csourcetypical, DSC 10 C/min
Max service temperaturenot sourced125°CsourceUL 746B RTI, tensile strength, 1.5 mm
Values for6061-T6/T651, Kaiser Aluminum typical properties; Poisson from MIL-HDBK-5JCovestro Makrolon 2405 general-purpose PC (MVR 19), Covestro technical datasheet version 2026-09-28, typical values

Every value links to the document that states it. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.

Questions

Is Aluminum 6061-T6 stronger than Plastic Polycarbonate?

Aluminum 6061-T6 is stronger: its yield strength is 276 MPa against 65 MPa for Plastic Polycarbonate (4.25x).

Which is lighter, Aluminum 6061-T6 or Plastic Polycarbonate?

Plastic Polycarbonate is lighter: 1,200 kg/m³ against 2,700 kg/m³ for Aluminum 6061-T6.

Which is stiffer, Aluminum 6061-T6 or Plastic Polycarbonate?

Aluminum 6061-T6 is stiffer: Young's modulus 68.3 GPa against 2.4 GPa for Plastic Polycarbonate, so the same part in Aluminum 6061-T6 deflects less under the same load.

Which is lighter for the same job, Aluminum 6061-T6 or Plastic Polycarbonate?

For the same stiffness or strength: Aluminum 6061-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam; Plastic Polycarbonate is lighter for a strong panel or plate.

Part that must beAluminum 6061-T6Plastic Polycarbonate
Stiff rod or tie (tension)lighter12.6x heavier
Stiff beam (bending)lighter2.37x heavier
Stiff panel or platelighter36% heavier
Strong rod or tielighter1.89x heavier
Strong beamlighter17% heavier
Strong panel or plate9% heavierlighter

For the same stiffness or strength, mass scales with density over stiffness (or strength) raised to a power set by how the part is loaded: 1 for a rod in tension, 1/2 for a beam in bending, 1/3 for a panel (the standard material-selection indices).

Which conducts heat better, Aluminum 6061-T6 or Plastic Polycarbonate?

Aluminum 6061-T6 conducts heat better: 167 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.

Which expands less with temperature?

Aluminum 6061-T6 expands less: 23.6 µm/m·K against 65 µm/m·K for Plastic Polycarbonate.

Among 59 materials

1k10k0.1110100Density (kg/m³)Young's modulus (GPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonAluminumSteelIronTitaniumSteel AISI 1018Stainless 304Stainless 316Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless 303Stainless 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelAluminum 6061-T6Plastic Polycarbonate
Stiffness against density
1k10k101001kDensity (kg/m³)Yield strength (MPa)Plastic PLAPlastic PETGPlastic ABSPlastic TPUPlastic NylonRubberAluminumSteelIronTitaniumSteel AISI 1018Stainless 304Stainless 316Aluminum 7075-T6Brass C360Copper C110GlassSteel AISI 1045Steel AISI 4340Steel A992Stainless 303Stainless 17-4PHAluminum 2024-T351Aluminum 5052-H32Aluminum 7050-T7451Titanium Ti-6Al-4VBrass C260Nickel Inconel 718Magnesium AZ31B-H24Zinc Zamak 3Plastic ABS (bulk/injection)Plastic POM/AcetalPlastic Nylon PA6Plastic Nylon PA66Plastic PEEKPlastic PTFEPlastic UHMWPEPlastic HDPEPlastic PolypropylenePlastic PMMAFDM ASAFDM PolycarbonateFDM PAHT-CFFDM HIPSSLA Resin Tough 2000SLA Resin Elastic 50ASLS PA12 NylonDMLS AlSi10Mg AluminumDMLS Ti-6Al-4V ELI TitaniumDMLS 316L Stainless SteelDMLS 17-4PH Stainless SteelBrickAluminum 6061-T6Plastic Polycarbonate
Strength against density

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