Nylon PA66

Nylon PA66 (Polyamide 66), produced from the polycondensation of hexamethylenediamine and adipic acid, is the most widely used engineering polyamide and the benchmark against which other nylons are measured. With higher tensile strength, better thermal resistance, and superior stiffness compared to PA6, PA66 is the material of choice for the most demanding mechanical applications — from automotive engine compartments to industrial gear systems. Its higher melting point (260°C) and improved mechanical performance at elevated temperatures make it indispensable where PA6 falls short, though its higher moisture sensitivity requires careful drying and processing control.

Mechanical Properties

• Density: 1.15 g/cm³
• Tensile Strength: 85 MPa
• Yield Strength: 80 MPa
• Elongation at Break: 50–150%
• Flexural Modulus: 3,000 MPa
• Hardness (Rockwell): R 80 (M scale: M75)
• Heat Deflection Temperature: 90°C @ 1.8 MPa; 220°C @ 0.45 MPa
• Melting Point: 260°C
• Thermal Conductivity: 0.25 W/m·K
• Coefficient of Thermal Expansion: 8.0 × 10⁻⁵ /°C
• Water Absorption: 4.5–8.0% (equilibrium)
• Flammability Rating: V-2 (UL94)

Advantages

🟢  Higher tensile strength (85 MPa vs PA6's 80 MPa) and superior stiffness across a wider temperature range

🟢  Excellent wear resistance with low friction coefficient; performs reliably as a self-lubricating bearing material at temperatures up to 120°C

🟢  Outstanding fatigue resistance — maintains mechanical integrity through millions of loading cycles

🟢  Good chemical resistance to oils, greases, fuels, and hydrocarbon solvents

🟢  Excellent creep resistance at elevated temperatures; dimensions remain stable under sustained load

🟢  Glass fiber and carbon fiber reinforced grades available for demanding structural applications (HDT up to 250°C)

Machining & Manufacturing

Common Applications