Premium Nylon Fasteners: Screws, Hex Nuts, Flat Washers & Custom Parts

Nylon 6/6 is a polyamide produced from hexamethylenediamine and adipic acid. While it offers many advantages, it also has limitations that engineers must weigh when selecting fasteners and custom parts.

Key Limitations of Nylon

• Hygroscopic Nature: Nylon readily absorbs moisture from the air, which can alter part dimensions.
• UV Sensitivity: Without additives, it degrades under sunlight.
• Chemical Resistance: It struggles in strong acids and halogens; acceptable in ketones and hydrogenated hydrocarbons but still not ideal.
• Temperature Limits: Continuous service temperature is 223 °F (106 °C). It should not be used in ovens or boiling water.
• Flammability: UL 94V‑2 rating—nylon melts before it burns.
• Mechanical Strength: Ultimate tensile strength is ~10,000 psi; composites like FRP/G10 reach 45,000 psi.

Why Nylon Remains Popular

Despite these drawbacks, nylon is one of the world’s most widely used plastics, driving a $30 B industry in 2020. Roughly one‑third of that revenue comes from automotive applications, a quarter from engineered plastics such as fasteners and custom components, with the rest in textiles, electronics, and more. The most common grades are Nylon 6/6, Nylon 6, Nylon 4/6, and Nylon 612.

Key Characteristics for Fastener Applications

Electrical Insulation

• With an electrical resistivity of 1,500 V/mil, nylon is an excellent insulator, making it ideal for screws, hex nuts, washers, cable ties, spacers, standoffs, and many PCB components.

Water Repellency

• While hygroscopic, nylon is water‑repellent, allowing quick drying—suitable for automotive parts that encounter occasional moisture but do not require tight tolerances.

UV Stabilization

• When treated with UV stabilizers, nylon resists sun‑induced degradation. For products that remain indoors (e.g., carpets) or are shielded from sunlight, this is often unnecessary.

Compatibility with Hydrocarbons

• Derived from petrochemicals, nylon performs well in gasoline and kerosene, and is used in engine components such as bushings, oil containers, and crankcase covers. Nylon 612 has found use in fuel line applications.

Wear Resistance & Lubricity

• Good inherent wear resistance, further enhanced by additives like molybdenum disulfide—critical for bushings and bearings in engineered plastics.

Service Temperature

• Although 223 °F is modest for engineered plastics, it is adequate for many automotive exterior parts (headlamp bezels, wheel covers, fuel caps) and everyday items like clothing and tents.

Melting Behavior

• Nylon tends to melt rather than ignite, which can be advantageous in safety‑critical applications.

Breakaway Applications

• Its moderate strength makes nylon suitable for components designed to fail under load. Adding glass fiber can raise tensile strength to ~32,000 psi, a 200‑fold increase over the base resin.

Alternatives to Nylon

• Emerging plastics—polypropylene, PVDF, para‑aramid fibers, and bio‑absorbable polymers—offer comparable or superior performance at lower cost, challenging nylon’s dominance.