Plastic ABS (bulk/injection) vs. Plastic PMMA

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

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

Plastic PMMABulk polymer (molded or machined)

Mechanical
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Yield strength	45MPasourcetypical, tensile stress at yield 23 °C	not given (tensile used)
Ultimate tensile strength	not sourced	80MPasourcetypical, 23 °C
Compressive strength	not sourced	110MPasourcecompressive yield stress, typical
Flexural strength	65MPasourcetypical, 23 °C	115MPasourcetypical
Elongation at break	10%sourcenominal strain at break, 23 °C	5.5%sourcetypical
Young's modulus (stiffness)	2.3GPasourcetypical	3.3GPasourcetypical, short-term
Density	1,040kg/m³sourcetypical14% lighter	1,190kg/m³sourcetypical
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	0.39sourcetypical, ABS family (Covestro Part and Mold Design guide, Table 3-1)	0.37sourcetypical
Shear modulus	0.827GPa	1.2GPa46% stiffer in shear
Bulk modulus	3.48GPa	4.23GPa
Speed of sound	1,487m/s	1,665m/s
Thermal
Thermal conductivity	0.17W/m·Ksourcetypical	0.19W/m·Ksourcetypical12% more heat through a fin
Thermal expansion	80–110µm/m·Ksourcerange	70µm/m·Ksource0-50 °C
100 mm part over a 50 °C swing	475µm growth	350µm growth36% less
Specific heat	not sourced	1,470J/kg·Ksourcetypical
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	94°CsourceHDT 1.8 MPa (annealed 4 h/80 °C)	80°Csourcemax. permanent service temperature
Values for	INEOS Styrolution Terluran GP-22 general-purpose injection-molding ABS, ISO typical values (TDS revision 08/01/2022)	Röhm PLEXIGLAS GS 0F00 cast acrylic sheet, typical values at 23 °C / 50 % RH (Röhm Technical Information Ref. No. 211-1)

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 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 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).

Among 59 materials

Stiffness against density

Strength against density