Plastic ABS (bulk/injection) vs. Plastic PMMA

Compare Plastic ABS (bulk/injection) vs. Plastic PMMA strength, stiffness, weight and thermal properties.

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

Plastic PMMABulk polymer (molded or machined)

Mechanical	Plastic ABS (bulk/injection)	Plastic PMMA
Yield strength	45MPa1	not given (tensile used)
Ultimate tensile strength	not stated (yield given)	80MPa2
Compressive strength	not sourced	110MPa2
Flexural strength	65MPa1	115MPa21.77x stronger in bending
Elongation at break	10%11.82x more ductile	5.5%2
Young's modulus (stiffness)	2.3GPa1	3.3GPa243% stiffer
Density	1,040kg/m³114% lighter	1,190kg/m³2
Strength to weight	43.3kN·m/kg	67.2kN·m/kg1.55x higher
Stiffness to weight	2.21MN·m/kg	2.77MN·m/kg25% higher
Poisson's ratio	0.393	0.372
Shear modulus	0.827GPa	1.2GPa46% stiffer in shear
Bulk modulus	3.48GPa	4.23GPa21% higher
Speed of sound	1,487m/s	1,665m/s12% faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic ABS (bulk/injection)	Plastic PMMA
Thermal conductivity	0.17W/m·K1	0.19W/m·K212% more heat through a fin
Thermal expansion	range80–110µm/m·K1	0-50 °C70µm/m·K2
100 mm part over a 50 °C swing	475µm growth	350µm growth36% less
Specific heat	not sourced	1,470J/kg·K2
Heats up and cools (diffusivity)	not sourced	0.109mm²/s
Thermal shock resistance	21.4W/m	41.5W/m1.94x more resistant
Max service temperature	HDT 1.8 MPa94°C1	80°C2

Thermal conductivity against densityHigher and further left: spreads more heat for its weight

Thermal expansion against thermal conductivityLower and further right: warps less when heated

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Sources3 documents: INEOS Styrolution, Röhm, Covestro

Plastic ABS (bulk/injection): INEOS Styrolution Terluran GP-22 general-purpose injection-molding ABS, ISO typical values (TDS revision 08/01/2022)
Plastic PMMA: Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)

1
Terluran GP-22 (ABS) Product Data SheetINEOS StyrolutionPlastic ABS (bulk/injection) · Yield strength: typical, tensile stress at yield 23 °CPlastic ABS (bulk/injection) · Flexural strength: typical, 23 °CPlastic ABS (bulk/injection) · Elongation at break: nominal strain at break, 23 °CPlastic ABS (bulk/injection) · Young's modulus (stiffness): typicalPlastic ABS (bulk/injection) · Density: typicalPlastic ABS (bulk/injection) · Thermal conductivity: typicalPlastic ABS (bulk/injection) · Thermal expansion: rangePlastic ABS (bulk/injection) · Max service temperature: HDT 1.8 MPa (annealed 4 h/80 °C)
2
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
3
Engineering Polymers Part and Mold Design: Thermoplastics, A Design GuideCovestroarchived copyPlastic ABS (bulk/injection) · Poisson's ratio: typical, ABS family (Covestro Part and Mold Design guide, Table 3-1)

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 ABS (bulk/injection) stronger than Plastic PMMA?

Plastic PMMA is stronger: its tensile strength is 80 MPa against yield strength 45 MPa for Plastic ABS (bulk/injection) (1.78x).

Which is lighter, Plastic ABS (bulk/injection) or Plastic PMMA?

Plastic ABS (bulk/injection) is lighter: 1,040 kg/m³ against 1,190 kg/m³ for Plastic PMMA.

Which is stiffer, Plastic ABS (bulk/injection) or Plastic PMMA?

Plastic PMMA is stiffer: Young's modulus 3.3 GPa against 2.3 GPa for Plastic ABS (bulk/injection), so the same part in Plastic PMMA deflects less under the same load.

Which is lighter for the same job, Plastic ABS (bulk/injection) or Plastic PMMA?

For the same stiffness or strength: Plastic ABS (bulk/injection) is lighter for a stiff panel or plate; Plastic PMMA is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie, strong beam, strong panel or plate.

Part that must be	Plastic ABS (bulk/injection)	Plastic PMMA
Stiff rod or tie (tension)	25% heavier	lighter
Stiff beam (bending)	5% heavier	lighter
Stiff panel or plate	lighter	1% heavier
Strong rod or tie	1.55x heavier	lighter
Strong beam	28% heavier	lighter
Strong panel or plate	17% 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 is more ductile, Plastic ABS (bulk/injection) or Plastic PMMA?

Plastic ABS (bulk/injection) stretches further before it breaks: 10% elongation at break against 5.5% for Plastic PMMA.

Thermal

Which conducts heat better, Plastic ABS (bulk/injection) or Plastic PMMA?

Plastic PMMA conducts heat better: 0.19 W/m·K against 0.17 W/m·K for Plastic ABS (bulk/injection).

Which expands less with temperature?

Plastic PMMA expands less: 70 µm/m·K against 95 µm/m·K for Plastic ABS (bulk/injection).