Plastic ABS vs. Plastic PMMA

Compare Plastic ABS vs. Plastic PMMA strength, stiffness, weight and thermal properties.

Plastic PMMABulk polymer (molded or machined)

Mechanical	Plastic ABS	Plastic PMMA
Yield strength	38.1MPa1	not given (tensile used)
Ultimate tensile strength	38.1MPa1	80MPa22.1x stronger
Compressive strength	not sourced	110MPa2
Flexural strength	61.1MPa1	115MPa21.88x stronger in bending
Elongation at break	4.6%1	5.5%220% more ductile
Young's modulus (stiffness)	1.96GPa1	3.3GPa21.68x stiffer
Density	1,100kg/m³1	1,190kg/m³2
Strength to weight	34.6kN·m/kg	67.2kN·m/kg1.94x higher
Stiffness to weight	1.78MN·m/kg	2.77MN·m/kg1.55x higher
Poisson's ratio	base material0.393	0.372
Shear modulus	0.706GPa	1.2GPa1.71x stiffer in shear
Bulk modulus	2.97GPa	4.23GPa42% higher
Speed of sound	1,336m/s	1,665m/s25% faster

Stiffness against densityHigher and further left: stiffer for its weight

Strength against densityHigher and further left: stronger for its weight

Thermal	Plastic ABS	Plastic PMMA
Thermal conductivity	base material0.17W/m·K4	0.19W/m·K212% more heat through a fin
Thermal expansion	base material80–110µm/m·K4	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	21.2W/m	41.5W/m1.96x more resistant
Glass transition	101°C1	not sourced
Max service temperature	HDT 0.455 MPa86.6°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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Sources4 documents: UltiMaker, Röhm, Covestro, INEOS Styrolution

Plastic ABS: Ultimaker ABS, 3D-printed specimens, XY (flat); Ultimaker S5 Pro, engineering intent profile, 0.15 mm layer height, AA 0.4 print core, 100% infill, Cura 4.9, printed one-at-a-time, conditioned >=24 h at room temperature. TDS v5.00, April 20, 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
Ultimaker ABS Technical Data Sheet, v5.00UltiMakerarchived copyPlastic ABS · Yield strength: typicalPlastic ABS · Ultimate tensile strength: typical, peak stress (= stress at yield)Plastic ABS · Flexural strength: typicalPlastic ABS · Elongation at break: typicalPlastic ABS · Young's modulus (stiffness): typicalPlastic ABS · Density: typicalPlastic ABS · Glass transition: typicalPlastic ABS · Max service temperature: HDT 0.455 MPa (printed specimens)
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 · Poisson's ratio: base material: ABS family typical (Covestro Part and Mold Design guide, Table 3-1)
4
Terluran GP-22 (ABS) Product Data SheetINEOS StyrolutionPlastic ABS · Thermal conductivity: base material: INEOS Styrolution Terluran GP-22 injection-molding ABS, typicalPlastic ABS · Thermal expansion: base material: INEOS Styrolution Terluran GP-22 injection-molding ABS, range

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.

Plastic ABS is 3D printed: its properties depend on build direction and print settings; these are typical values.

Questions

Mechanical

Is Plastic ABS stronger than Plastic PMMA?

Plastic PMMA is stronger: its tensile strength is 80 MPa against yield strength 38.1 MPa for Plastic ABS (2.1x).

Which is lighter, Plastic ABS or Plastic PMMA?

Plastic ABS is lighter: 1,100 kg/m³ against 1,190 kg/m³ for Plastic PMMA.

Which is stiffer, Plastic ABS or Plastic PMMA?

Plastic PMMA is stiffer: Young's modulus 3.3 GPa against 1.96 GPa for Plastic ABS, so the same part in Plastic PMMA deflects less under the same load.

Which is lighter for the same job, Plastic ABS or Plastic PMMA?

For the same stiffness or strength: Plastic PMMA 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 ABS	Plastic PMMA
Stiff rod or tie (tension)	1.55x heavier	lighter
Stiff beam (bending)	20% heavier	lighter
Stiff panel or plate	10% heavier	lighter
Strong rod or tie	1.94x heavier	lighter
Strong beam	1.52x heavier	lighter
Strong panel or plate	34% 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 or Plastic PMMA?

Plastic PMMA stretches further before it breaks: 5.5% elongation at break against 4.6% for Plastic ABS.

Thermal

Which conducts heat better, Plastic ABS or Plastic PMMA?

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

Which expands less with temperature?

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