Plastic Nylon PA66 vs. Plastic Polycarbonate

Compare Plastic Nylon PA66 vs. Plastic Polycarbonate strength, stiffness, weight and thermal properties.

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Plastic Nylon PA66Bulk polymer (molded or machined)

Plastic PolycarbonateBulk polymer (molded or machined)

Mechanical
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Yield strength	85MPasourcetypical, dry	65MPasourcetypical, tensile yield
Ultimate tensile strength	not sourced	65MPasourcetypical, stress at break
Flexural strength	not sourced	97MPasourcetypical, flexural strength
Elongation at break	30%sourcenominal strain at break, dry	125%sourcetypical, strain at break
Young's modulus (stiffness)	3GPasourcetypical, dry	2.4GPasourcetypical
Density	1,130kg/m³sourcetypical	1,200kg/m³sourcetypical
Strength to weight	75.2kN·m/kg39% higher	54.2kN·m/kg
Stiffness to weight	2.65MN·m/kg33% higher	2MN·m/kg
Poisson's ratio	0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)	0.38sourcetypical, polycarbonate family (Covestro Part and Mold Design guide, Table 3-1)
Shear modulus	1.07GPa23% stiffer in shear	0.87GPa
Bulk modulus	5GPa	3.33GPa
Speed of sound	1,629m/s	1,414m/s
Thermal
Thermal conductivity	0.33W/m·Ksourcetypical	0.2W/m·Ksourcetypical, through-plane, 23 C
Thermal expansion	98µm/m·Ksourcelongitudinal, 23-55 °C	65µm/m·Ksourcetypical, 23-55 C, parallel and normal
100 mm part over a 50 °C swing	490µm growth	325µm growth1.51x less
Specific heat	1,700J/kg·Ksourcetypical	1,172J/kg·Ksourcetypical (guide value), Bayer ASTM datasheet for Makrolon 2405, ASTM D 2766
Heats up and cools (diffusivity)	0.172mm²/s21% faster	0.142mm²/s
Thermal shock resistance	57.2W/m11% more resistant	51.7W/m
Melting point	260°CsourceDSC	not sourced
Glass transition	not sourced	144°Csourcetypical, DSC 10 C/min
Max service temperature	101°CsourceIEC 60216 temperature index, 20000 h	125°CsourceUL 746B RTI, tensile strength, 1.5 mm
Values for	BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods)	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.

Questions

Is Plastic Nylon PA66 stronger than Plastic Polycarbonate?

Plastic Nylon PA66 is stronger: its yield strength is 85 MPa against 65 MPa for Plastic Polycarbonate (31%).

Which is lighter, Plastic Nylon PA66 or Plastic Polycarbonate?

Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 1,200 kg/m³ for Plastic Polycarbonate.

Which is stiffer, Plastic Nylon PA66 or Plastic Polycarbonate?

Plastic Nylon PA66 is stiffer: Young's modulus 3 GPa against 2.4 GPa for Plastic Polycarbonate, so the same part in Plastic Nylon PA66 deflects less under the same load.

Which is lighter for the same job, Plastic Nylon PA66 or Plastic Polycarbonate?

For the same stiffness or strength: Plastic Nylon PA66 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 Nylon PA66	Plastic Polycarbonate
Stiff rod or tie (tension)	lighter	33% heavier
Stiff beam (bending)	lighter	19% heavier
Stiff panel or plate	lighter	14% heavier
Strong rod or tie	lighter	39% heavier
Strong beam	lighter	27% heavier
Strong panel or plate	lighter	21% heavier

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 Nylon PA66 or Plastic Polycarbonate?

Plastic Nylon PA66 conducts heat better: 0.33 W/m·K against 0.2 W/m·K for Plastic Polycarbonate.

Which expands less with temperature?

Plastic Polycarbonate expands less: 65 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.

Among 59 materials

Stiffness against density

Strength against density