Plastic PETG vs. Plastic Polycarbonate

Compare Plastic PETG vs. Plastic Polycarbonate strength, stiffness, weight and thermal properties.

Change either side

Plastic PolycarbonateBulk polymer (molded or machined)

Mechanical
Try it on a partA bracket to run stress or thermal on, free in your browser	Open in LessCAD	Open in LessCAD
Yield strength	46.2MPasourcetypical	65MPasourcetypical, tensile yield
Ultimate tensile strength	46.2MPasourcetypical, peak stress (= stress at yield)	65MPasourcetypical, stress at break
Flexural strength	78.9MPasourcetypical	97MPasourcetypical, flexural strength
Elongation at break	7.6%sourcetypical	125%sourcetypical, strain at break
Young's modulus (stiffness)	1.94GPasourcetypical	2.4GPasourcetypical24% stiffer
Density	1,270kg/m³sourcetypical	1,200kg/m³sourcetypical
Strength to weight	36.4kN·m/kg	54.2kN·m/kg49% higher
Stiffness to weight	1.53MN·m/kg	2MN·m/kg31% higher
Poisson's ratio	not sourced	0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus	not sourced	0.87GPa
Bulk modulus	not sourced	3.33GPa
Speed of sound	1,236m/s	1,414m/s
Thermal
Thermal conductivity	0.21W/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical	0.2W/m·Ksourcetypical, through-plane, 23 C
Thermal expansion	51µm/m·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), typical	65µm/m·Ksourcetypical, 23-55 C, parallel and normal
100 mm part over a 50 °C swing	255µm growth27% less	325µm growth
Specific heat	1,300J/kg·Ksourcebase material: Eastman Eastar Copolyester 6763 (PETG), DSC at 60 °C (lowest temperature listed)	1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766
Heats up and cools (diffusivity)	0.127mm²/s	0.142mm²/s12% faster
Thermal shock resistance	not sourced	51.7W/m
Glass transition	77.4°Csourcetypical	144°Csourcetypical, DSC 10 C/min
Max service temperature	76.2°CsourceHDT 0.455 MPa (printed specimens)	125°CsourceUL 746B RTI, tensile strength, 1.5 mm
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.	Covestro Makrolon 2405 general-purpose PC (MVR 19), Covestro technical datasheet version 2026-09-28, typical values

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 Polycarbonate?

Plastic Polycarbonate is stronger: its yield strength is 65 MPa against 46.2 MPa for Plastic PETG (41%).

Which is lighter, Plastic PETG or Plastic Polycarbonate?

Plastic Polycarbonate is lighter: 1,200 kg/m³ against 1,270 kg/m³ for Plastic PETG.

Which is stiffer, Plastic PETG or Plastic Polycarbonate?

Plastic Polycarbonate is stiffer: Young's modulus 2.4 GPa against 1.94 GPa for Plastic PETG, so the same part in Plastic Polycarbonate deflects less under the same load.

Which is lighter for the same job, Plastic PETG or Plastic Polycarbonate?

For the same stiffness or strength: Plastic Polycarbonate 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 Polycarbonate
Stiff rod or tie (tension)	31% heavier	lighter
Stiff beam (bending)	18% heavier	lighter
Stiff panel or plate	14% heavier	lighter
Strong rod or tie	49% heavier	lighter
Strong beam	33% heavier	lighter
Strong panel or plate	26% 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 PETG or Plastic Polycarbonate?

Plastic PETG conducts heat better: 0.21 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.

Which expands less with temperature?

Plastic PETG expands less: 51 µm/m·K against 65 µm/m·K for Plastic Polycarbonate.

Among 59 materials

Stiffness against density

Strength against density