Aluminum A380 vs. Plastic PEEK

Q: Is Aluminum A380 stronger than Plastic PEEK?

Aluminum A380 is stronger: its yield strength is 160 MPa against 98 MPa for Plastic PEEK (1.63x).

Q: Which is lighter, Aluminum A380 or Plastic PEEK?

Plastic PEEK is lighter: 1,300 kg/m³ against 2,713 kg/m³ for Aluminum A380.

Q: Which is stiffer, Aluminum A380 or Plastic PEEK?

Aluminum A380 is stiffer: Young's modulus 71 GPa against 4 GPa for Plastic PEEK, so the same part in Aluminum A380 deflects less under the same load.

Q: Which is lighter for the same job, Aluminum A380 or Plastic PEEK?

For the same stiffness or strength: Aluminum A380 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate; Plastic PEEK is lighter for a strong rod or tie, strong beam, strong panel or plate.

Q: Which conducts heat better, Aluminum A380 or Plastic PEEK?

Aluminum A380 conducts heat better: 96.2 W/m·K against 0.29 W/m·K for Plastic PEEK.

Q: Which expands less with temperature?

Aluminum A380 expands less: 21.8 µm/m·K against 55 µm/m·K for Plastic PEEK.

Compare Aluminum A380 vs. Plastic PEEK strength, stiffness, weight and thermal properties.

Change either side

Aluminum A380Cast

Plastic PEEKBulk polymer (molded or machined)

Mechanical
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Yield strength	160MPasourcetypical, 25 °C	98MPasourcetypical, tensile yield
Ultimate tensile strength	320MPasourcetypical, 25 °C	not sourced
Compressive strength	not sourced	125MPasourcetypical, 23 C
Flexural strength	not sourced	165MPasourcetypical, flexural stress at yield, 23 C
Elongation at break	3.5%sourcetypical	25%sourcetypical, at break
Young's modulus (stiffness)	71GPasourcetypical, 25 °C	4GPasourcetypical (nominal)
Density	2,713kg/m³sourcetypical at 68 °F	1,300kg/m³sourcetypical (crystalline)
Strength to weight	59kN·m/kg	75.4kN·m/kg28% higher
Stiffness to weight	26.2MN·m/kg8.51x higher	3.08MN·m/kg
Poisson's ratio	not sourced	0.38sourcetypical
Shear modulus	not sourced	1.45GPa
Bulk modulus	not sourced	5.56GPa
Speed of sound	5,116m/s	1,754m/s
Thermal
Thermal conductivity	96.2W/m·Ksourcetypical at 68 °F	0.29W/m·Ksourcetypical, average, 23 C
Thermal expansion	21.8µm/m·Ksourcetypical, 68-572 °F (20-300 °C)	55µm/m·Ksourceaverage of flow/cross-flow, below Tg (<143 C)
100 mm part over a 50 °C swing	109µm growth2.53x less	275µm growth
Specific heat	963J/kg·Ksourcetypical at 68 °F	2,200J/kg·Ksourcetypical, 23 °C, DSC (Victrex PEEK 450G TDS, revision Jul 2012)
Heats up and cools (diffusivity)	36.8mm²/s363x faster	0.101mm²/s
Thermal shock resistance	not sourced	80.1W/m
Melting point	not sourced	343°Csourcetypical, DSC
Glass transition	not sourced	143°Csourceonset (midpoint 150 C)
Max service temperature	not sourced	240°CsourceUL 746B RTI, mechanical strength (continuous use index)
Values for	A380 aluminium high-pressure die-casting alloy, typical properties; Rheocast Company (aluminium die caster, Germantown WI) A380 alloy data page.	Victrex PEEK 450G (unreinforced, injection moulded), Victrex TDS rev. March 2026; Poisson from Victrex fluid-management flyer (2020-07)

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 A380 stronger than Plastic PEEK?

Aluminum A380 is stronger: its yield strength is 160 MPa against 98 MPa for Plastic PEEK (1.63x).

Which is lighter, Aluminum A380 or Plastic PEEK?

Plastic PEEK is lighter: 1,300 kg/m³ against 2,713 kg/m³ for Aluminum A380.

Which is stiffer, Aluminum A380 or Plastic PEEK?

Aluminum A380 is stiffer: Young's modulus 71 GPa against 4 GPa for Plastic PEEK, so the same part in Aluminum A380 deflects less under the same load.

Which is lighter for the same job, Aluminum A380 or Plastic PEEK?

For the same stiffness or strength: Aluminum A380 is lighter for a stiff rod or tie (tension), stiff beam (bending), stiff panel or plate; Plastic PEEK is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum A380	Plastic PEEK
Stiff rod or tie (tension)	lighter	8.51x heavier
Stiff beam (bending)	lighter	2.02x heavier
Stiff panel or plate	lighter	25% heavier
Strong rod or tie	28% heavier	lighter
Strong beam	1.51x heavier	lighter
Strong panel or plate	1.63x 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, Aluminum A380 or Plastic PEEK?

Aluminum A380 conducts heat better: 96.2 W/m·K against 0.29 W/m·K for Plastic PEEK.

Which expands less with temperature?