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

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

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

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

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

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

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

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

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

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

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