Thermal conductivity against densityHigher and further left: spreads more heat for its weightThermal expansion against thermal conductivityLower and further right: warps less when heated
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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.
Plastic PMMA
Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)
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Ultradur B 4300 G6 Product InformationBASFPlastic PBT GF30 · Ultimate tensile strength: stress at break, 23 °CPlastic PBT GF30 · Flexural strength: typical, 23 °CPlastic PBT GF30 · Elongation at break: strain at break, 23 °CPlastic PBT GF30 · Young's modulus (stiffness): typical, 23 °CPlastic PBT GF30 · Density: typicalPlastic PBT GF30 · Thermal conductivity: typical (DIN 52612-1)Plastic PBT GF30 · Thermal expansion: longitudinal (flow), mean 23-55 °CPlastic PBT GF30 · Specific heat: typical, 23 °CPlastic PBT GF30 · Melting point: DSC (ISO 11357)Plastic PBT GF30 · Max service temperature: HDT 1.8 MPa
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PLEXIGLAS GS and XT Technical Information (Ref. No. 211-1)Röhmarchived copyPlastic PMMA · Ultimate tensile strength: typical, 23 °CPlastic PMMA · Compressive strength: compressive yield stress, typicalPlastic PMMA · Flexural strength: typicalPlastic PMMA · Elongation at break: typicalPlastic PMMA · Young's modulus (stiffness): typical, short-termPlastic PMMA · Density: typicalPlastic PMMA · Poisson's ratio: typicalPlastic PMMA · Thermal conductivity: typicalPlastic PMMA · Thermal expansion: 0-50 °CPlastic PMMA · Specific heat: typicalPlastic PMMA · Max service temperature: max. permanent service temperature
Each number points to the document that states it, with the exact basis. Values without a number are computed from the sourced ones. "Not sourced" means no citable source states it (or only a specification minimum); figures computed from it are left out too.
Questions
Mechanical
Is Plastic PBT GF30 stronger than Plastic PMMA?
Plastic PBT GF30 is stronger: its tensile strength is 140 MPa against 80 MPa for Plastic PMMA (1.75x).
Which is lighter, Plastic PBT GF30 or Plastic PMMA?
Plastic PMMA is lighter: 1,190 kg/m³ against 1,530 kg/m³ for Plastic PBT GF30.
Which is stiffer, Plastic PBT GF30 or Plastic PMMA?
Plastic PBT GF30 is stiffer: Young's modulus 9.8 GPa against 3.3 GPa for Plastic PMMA, so the same part in Plastic PBT GF30 deflects less under the same load.
Which is lighter for the same job, Plastic PBT GF30 or Plastic PMMA?
For the same stiffness or strength: Plastic PBT GF30 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 PBT GF30
Plastic PMMA
Stiff rod or tie (tension)
lighter
2.31x heavier
Stiff beam (bending)
lighter
34% heavier
Stiff panel or plate
lighter
12% heavier
Strong rod or tie
lighter
36% heavier
Strong beam
lighter
13% heavier
Strong panel or plate
lighter
3% 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 is more ductile, Plastic PBT GF30 or Plastic PMMA?
Plastic PMMA stretches further before it breaks: 5.5% elongation at break against 3% for Plastic PBT GF30.
Thermal
Which conducts heat better, Plastic PBT GF30 or Plastic PMMA?
Plastic PBT GF30 conducts heat better: 0.27 W/m·K against 0.19 W/m·K for Plastic PMMA.
Which expands less with temperature?
Plastic PBT GF30 expands less: 25 µm/m·K against 70 µm/m·K for Plastic PMMA.