Plastic Nylon PA66 vs. Titanium Ti-6Al-4V

Compare Plastic Nylon PA66 vs. Titanium Ti-6Al-4V strength, stiffness, weight and thermal properties.

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Plastic Nylon PA66Bulk polymer (molded or machined)

Mechanical
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Yield strength	85MPasourcetypical, dry	885MPasourcetypical, plate (>0.187 in), annealed, 0.2% offset
Ultimate tensile strength	not sourced	940MPasourcetypical, plate, annealed
Elongation at break	30%sourcenominal strain at break, dry	16%sourcetypical, in 2 in., plate annealed
Young's modulus (stiffness)	3GPasourcetypical, dry	107–122GPasourcetypical range, 20 °C
Density	1,130kg/m³sourcetypical	4,430kg/m³sourcenominal
Strength to weight	75.2kN·m/kg	200kN·m/kg2.66x higher
Stiffness to weight	2.65MN·m/kg	25.8MN·m/kg9.74x higher
Poisson's ratio	0.4sourcebase material: unfilled polyamide (PA), conditioned, maker design-guide family value (Covestro Table 3-1)	0.342sourcemean of TIMET measurements
Shear modulus	1.07GPa	42.7GPa39.8x stiffer in shear
Bulk modulus	5GPa	121GPa
Speed of sound	1,629m/s	5,084m/s
Thermal
Thermal conductivity	0.33W/m·Ksourcetypical	6.6W/m·Ksourcetypical, 20 °C, mill annealed
Thermal expansion	98µm/m·Ksourcelongitudinal, 23-55 °C	9µm/m·Ksourcetypical, mean 0-100 °C
100 mm part over a 50 °C swing	490µm growth	45µm growth10.9x less
Specific heat	1,700J/kg·Ksourcetypical	580J/kg·Ksourcetypical, 20 °C
Heats up and cools (diffusivity)	0.172mm²/s	2.57mm²/s15x faster
Thermal shock resistance	57.2W/m	3,730W/m65.2x more resistant
Melting point	260°CsourceDSC	1,630–1,650°Csourcemelting range
Max service temperature	101°CsourceIEC 60216 temperature index, 20000 h	400°Csourceupper recommended use temperature
Values for	BASF Ultramid A3K (PA66, unreinforced injection-moulding grade), Product Information 02/2026, dry values (ISO methods)	TIMETAL 6-4 (Ti-6Al-4V Grade 5) annealed plate typical (TIMET properties manual) + TIMET datasheet TMC-0150 physical properties

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 Titanium Ti-6Al-4V?

Titanium Ti-6Al-4V is stronger: its yield strength is 885 MPa against 85 MPa for Plastic Nylon PA66 (10.4x).

Which is lighter, Plastic Nylon PA66 or Titanium Ti-6Al-4V?

Plastic Nylon PA66 is lighter: 1,130 kg/m³ against 4,430 kg/m³ for Titanium Ti-6Al-4V.

Which is stiffer, Plastic Nylon PA66 or Titanium Ti-6Al-4V?

Titanium Ti-6Al-4V is stiffer: Young's modulus 115 GPa against 3 GPa for Plastic Nylon PA66, so the same part in Titanium Ti-6Al-4V deflects less under the same load.

Which is lighter for the same job, Plastic Nylon PA66 or Titanium Ti-6Al-4V?

For the same stiffness or strength: Plastic Nylon PA66 is lighter for a stiff panel or plate, strong panel or plate; Titanium Ti-6Al-4V is lighter for a stiff rod or tie (tension), stiff beam (bending), strong rod or tie, strong beam.

Part that must be	Plastic Nylon PA66	Titanium Ti-6Al-4V
Stiff rod or tie (tension)	9.74x heavier	lighter
Stiff beam (bending)	1.58x heavier	lighter
Stiff panel or plate	lighter	16% heavier
Strong rod or tie	2.66x heavier	lighter
Strong beam	22% heavier	lighter
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 Titanium Ti-6Al-4V?

Titanium Ti-6Al-4V conducts heat better: 6.6 W/m·K against 0.33 W/m·K for Plastic Nylon PA66.

Which expands less with temperature?

Titanium Ti-6Al-4V expands less: 9 µm/m·K against 98 µm/m·K for Plastic Nylon PA66.

Among 59 materials

Stiffness against density

Strength against density