Materials / Compare
Plastic PETG vs. Plastic PMMA
Compare Plastic PETG vs. Plastic PMMA strength, stiffness, weight and thermal properties.
| Try it on a partA bracket to run stress or thermal on, free in your browser | Open in LessCAD | Open in LessCAD |
|---|---|---|
| Mechanical | ||
| Yield strength | 46.2MPasourcetypical | not given (tensile used) |
| Ultimate tensile strength | 46.2MPasourcetypical, peak stress (= stress at yield) | 80MPasourcetypical, 23 °C |
| Compressive strength | not sourced | 110MPasourcecompressive yield stress, typical |
| Flexural strength | 78.9MPasourcetypical | 115MPasourcetypical46% stronger in bending |
| Elongation at break | 7.6%sourcetypical38% more ductile | 5.5%sourcetypical |
| Young's modulus (stiffness) | 1.94GPasourcetypical | 3.3GPasourcetypical, short-term |
| Density | 1,270kg/m³sourcetypical | 1,190kg/m³sourcetypical |
| Strength to weight | 36.4kN·m/kg | 67.2kN·m/kg1.85x higher |
| Stiffness to weight | 1.53MN·m/kg | 2.77MN·m/kg1.82x higher |
| Poisson's ratio | not sourced | 0.37sourcetypical |
| Shear modulus | not sourced | 1.2GPa |
| Bulk modulus | not sourced | 4.23GPa |
| Speed of sound | 1,236m/s | 1,665m/s |
| Thermal | ||
| Thermal conductivity | 0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical | 0.19W/m·Ksourcetypical |
| Thermal expansion | 51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical | 70µm/m·Ksource0-50 °C |
| 100 mm part over a 50 °C swing | 255µm growth37% less | 350µm growth |
| Specific heat | 1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed) | 1,470J/kg·Ksourcetypical |
| Heats up and cools (diffusivity) | 0.127mm²/s17% faster | 0.109mm²/s |
| Thermal shock resistance | not sourced | 41.5W/m |
| Glass transition | 77.4°Csourcetypical | not sourced |
| Max service temperature | 76.2°CsourceHDT 0.455 MPa (printed specimens) | 80°Csourcemax. permanent service temperature |
| Values for | Ultimaker PETG, 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 v1.00, April 29, 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.
Plastic PETG is 3D printed: its properties depend on build direction and print settings; these are typical values.
Questions
Is Plastic PETG stronger than Plastic PMMA?
Plastic PMMA is stronger: its tensile strength is 80 MPa against yield strength 46.2 MPa for Plastic PETG (1.73x).
Which is lighter, Plastic PETG or Plastic PMMA?
Plastic PMMA is lighter: 1,190 kg/m³ against 1,270 kg/m³ for Plastic PETG.
Which is stiffer, Plastic PETG or Plastic PMMA?
Plastic PMMA is stiffer: Young's modulus 3.3 GPa against 1.94 GPa for Plastic PETG, so the same part in Plastic PMMA deflects less under the same load.
Which is lighter for the same job, Plastic PETG 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 PETG | Plastic PMMA |
|---|---|---|
| Stiff rod or tie (tension) | 1.82x heavier | lighter |
| Stiff beam (bending) | 39% heavier | lighter |
| Stiff panel or plate | 27% heavier | lighter |
| Strong rod or tie | 1.85x heavier | lighter |
| Strong beam | 1.54x heavier | lighter |
| Strong panel or plate | 40% 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 PETG or Plastic PMMA?
Plastic PETG stretches further before it breaks: 7.6% elongation at break against 5.5% for Plastic PMMA.
Which conducts heat better, Plastic PETG or Plastic PMMA?
Plastic PETG conducts heat better: 0.21 W/m·K against 0.19 W/m·K for Plastic PMMA.
Which expands less with temperature?
Plastic PETG expands less: 51 µm/m·K against 70 µm/m·K for Plastic PMMA.