Aluminum 7075-T6 vs. Plastic ABS (bulk/injection)

Compare Aluminum 7075-T6 vs. Plastic ABS (bulk/injection) strength, stiffness, weight and thermal properties.

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Plastic ABS (bulk/injection)Bulk polymer (molded or machined)

Mechanical
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Yield strength	503MPasourcetypical, 0.2% offset, .500 in dia specimen	45MPasourcetypical, tensile stress at yield 23 °C
Ultimate tensile strength	572MPasourcetypical	not sourced
Flexural strength	not sourced	65MPasourcetypical, 23 °C
Elongation at break	11%sourcetypical, in 4D	10%sourcenominal strain at break, 23 °C
Young's modulus (stiffness)	71GPasourcetypical30.9x stiffer	2.3GPasourcetypical
Density	2,800kg/m³sourcenominal	1,040kg/m³sourcetypical
Strength to weight	180kN·m/kg4.15x higher	43.3kN·m/kg
Stiffness to weight	25.4MN·m/kg11.5x higher	2.21MN·m/kg
Poisson's ratio	0.33sourcetypical (handbook physical constant)	0.39sourcetypical, ABS family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus	26.7GPa32.3x stiffer in shear	0.827GPa
Bulk modulus	69.6GPa	3.48GPa
Speed of sound	5,036m/s	1,487m/s
Thermal
Thermal conductivity	130W/m·Ksourcetypical, 20 °C, T651	0.17W/m·Ksourcetypical
Thermal expansion	23.4µm/m·Ksourcetypical, mean 20-100 °C	80–110µm/m·Ksourcerange
100 mm part over a 50 °C swing	117µm growth4.06x less	475µm growth
Specific heat	960J/kg·Ksourcetypical, at 100 °C	not sourced
Heats up and cools (diffusivity)	48.4mm²/s	not sourced
Thermal shock resistance	26,370W/m1,235x more resistant	21.4W/m
Melting point	532–635°Csourcemelting range	not sourced
Max service temperature	not sourced	94°CsourceHDT 1.8 MPa (annealed 4 h/80 °C)
Values for	7075-T6/T651, Kaiser Aluminum rod & bar (mechanical) and sheet/coil/plate (physical) typical datasheets; Poisson from MIL-HDBK-5J	INEOS Styrolution Terluran GP-22 general-purpose injection-molding ABS, ISO typical values (TDS revision 08/01/2022)

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 7075-T6 stronger than Plastic ABS (bulk/injection)?

Aluminum 7075-T6 is stronger: its yield strength is 503 MPa against 45 MPa for Plastic ABS (bulk/injection) (11.2x).

Which is lighter, Aluminum 7075-T6 or Plastic ABS (bulk/injection)?

Plastic ABS (bulk/injection) is lighter: 1,040 kg/m³ against 2,800 kg/m³ for Aluminum 7075-T6.

Which is stiffer, Aluminum 7075-T6 or Plastic ABS (bulk/injection)?

Aluminum 7075-T6 is stiffer: Young's modulus 71 GPa against 2.3 GPa for Plastic ABS (bulk/injection), so the same part in Aluminum 7075-T6 deflects less under the same load.

Which is lighter for the same job, Aluminum 7075-T6 or Plastic ABS (bulk/injection)?

For the same stiffness or strength: Aluminum 7075-T6 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate, strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum 7075-T6	Plastic ABS (bulk/injection)
Stiff rod or tie (tension)	lighter	11.5x heavier
Stiff beam (bending)	lighter	2.06x heavier
Stiff panel or plate	lighter	17% heavier
Strong rod or tie	lighter	4.15x heavier
Strong beam	lighter	1.86x heavier
Strong panel or plate	lighter	24% heavier

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 7075-T6 or Plastic ABS (bulk/injection)?

Aluminum 7075-T6 conducts heat better: 130 W/m·K against 0.17 W/m·K for Plastic ABS (bulk/injection).

Which expands less with temperature?

Aluminum 7075-T6 expands less: 23.4 µm/m·K against 95 µm/m·K for Plastic ABS (bulk/injection).

Among 59 materials

Stiffness against density

Strength against density