Tough. Wear-resistant. The default for mechanical plastic parts.

Nylon chains contain polar amide groups that hydrogen-bond with water. PA6 and PA66 absorb 2–3% water at equilibrium (saturated humidity), which plasticizes the polymer: parts swell ~0.5–1% dimensionally, become 30% stronger in impact but 30% less stiff. For tight-tolerance applications, condition nylon to use-humidity before final machining. For dimensionally stable applications, use PA12 (0.3% water) or Delrin (0.2% water).

PA66 has higher crystallinity and therefore: 30 °C higher HDT (200 vs 170 °C), 20% higher tensile, better wear resistance, better dimensional stability. PA6 has: higher impact toughness, better moldability, lower cost (~1/5), available as large cast shapes. For most industrial machined parts, PA66. For impact-critical or large castings, PA6.

FDA-compliant nylon grades exist (PA6 and PA66 with FDA 21 CFR 177.1500 compliance) for food contact. Standard industrial nylon is not automatically food-safe. Specify food-grade explicitly for food processing equipment, kitchen tools, or beverage handling. For medical contact, use USP Class VI grades or consult our QA team.

Yes. Ultrasonic welding, vibration welding, hot-plate welding, and spin welding all work well on nylon. Adhesive bonding is more challenging — nylon's crystalline structure resists most adhesives, requiring surface treatment (flame, plasma, or chemical etch) before using epoxy or cyanoacrylate.

PA66 with 50% glass fiber (PA66-GF50) can reach 200 MPa tensile strength. Carbon-fiber-filled PA66 (PA66-CF30) reaches 250 MPa with lower density than glass. For extreme strength-to-weight, consider PEEK-CF30 at 220 MPa and higher temperature service — but at 15× the cost.