Aluminum A380 vs. Plastic PBT GF30

Compare Aluminum A380 vs. Plastic PBT GF30 strength, stiffness, weight and thermal properties.

Change either side

Plastic PBT GF30Bulk polymer (molded or machined)

Mechanical
Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD
Yield strength	160MPasourcetypical, 25 °C	not given (tensile used)
Ultimate tensile strength	320MPasourcetypical, 25 °C	140MPasourcestress at break, 23 °C
Flexural strength	not sourced	210MPasourcetypical, 23 °C
Elongation at break	3.5%sourcetypical	3%sourcestrain at break, 23 °C
Young's modulus (stiffness)	71GPasourcetypical, 25 °C	9.8GPasourcetypical, 23 °C
Density	2,713kg/m³sourcetypical at 68 °F	1,530kg/m³sourcetypical
Strength to weight	59kN·m/kg	91.5kN·m/kg1.55x higher
Stiffness to weight	26.2MN·m/kg4.09x higher	6.41MN·m/kg
Poisson's ratio	not sourced	not sourced
Shear modulus	not sourced	not sourced
Bulk modulus	not sourced	not sourced
Speed of sound	5,116m/s	2,531m/s
Thermal
Thermal conductivity	96.2W/m·Ksourcetypical at 68 °F	0.27W/m·Ksourcetypical (DIN 52612-1)
Thermal expansion	21.8µm/m·Ksourcetypical, 68-572 °F (20-300 °C)	25µm/m·Ksourcelongitudinal (flow), mean 23-55 °C
100 mm part over a 50 °C swing	109µm growth15% less	125µm growth
Specific heat	963J/kg·Ksourcetypical at 68 °F	1,050J/kg·Ksourcetypical, 23 °C
Heats up and cools (diffusivity)	36.8mm²/s219x faster	0.168mm²/s
Thermal shock resistance	not sourced	not sourced
Melting point	not sourced	223°CsourceDSC (ISO 11357)
Max service temperature	not sourced	205°CsourceHDT 1.8 MPa
Values for	A380 aluminium high-pressure die-casting alloy, typical properties; Rheocast Company (aluminium die caster, Germantown WI) A380 alloy data page.	BASF Ultradur B 4300 G6 (PBT, 30% glass fibre), injection moulding grade; product information sheet 09/2026, typical values for uncoloured product at 23 °C.

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 PBT GF30?

Aluminum A380 is stronger: its yield strength is 160 MPa against tensile strength 140 MPa for Plastic PBT GF30 (14%).

Which is lighter, Aluminum A380 or Plastic PBT GF30?

Plastic PBT GF30 is lighter: 1,530 kg/m³ against 2,713 kg/m³ for Aluminum A380.

Which is stiffer, Aluminum A380 or Plastic PBT GF30?

Aluminum A380 is stiffer: Young's modulus 71 GPa against 9.8 GPa for Plastic PBT GF30, so the same part in Aluminum A380 deflects less under the same load.

Which is lighter for the same job, Aluminum A380 or Plastic PBT GF30?

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 PBT GF30 is lighter for a strong rod or tie, strong beam, strong panel or plate.

Part that must be	Aluminum A380	Plastic PBT GF30
Stiff rod or tie (tension)	lighter	4.09x heavier
Stiff beam (bending)	lighter	1.52x heavier
Stiff panel or plate	lighter	9% heavier
Strong rod or tie	1.55x heavier	lighter
Strong beam	1.62x heavier	lighter
Strong panel or plate	1.66x 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 PBT GF30?

Aluminum A380 conducts heat better: 96.2 W/m·K against 0.27 W/m·K for Plastic PBT GF30.

Which expands less with temperature?

Aluminum A380 expands less: 21.8 µm/m·K against 25 µm/m·K for Plastic PBT GF30.

Among 72 materials

Stiffness against density

Strength against density