Nylon 6/6 (Polyamide) PA66
Comprehensive technical specification for Nylon 6/6 (Polyamide) covering Canadian stock sizing, machining parameters, common defects, and storage guidelines for industrial fabrication and CNC machining operations.
Material Overview & Common Uses
Nylon 6/6 (PA66) is a semi-crystalline engineering thermoplastic known for its high mechanical strength, stiffness, wear resistance, and low coefficient of friction. It exhibits excellent fatigue resistance and good chemical resistance to hydrocarbons, oils, and greases. Common applications in Canadian fabrication and machining include: precision gears, bearings, bushings, wear strips, conveyor components, jigs and fixtures, electrical insulators, and automotive under-hood parts. It is often selected as a lower-cost alternative to acetal (POM) in non-humidity-critical applications, though it absorbs moisture which can affect dimensional stability.
Core Technical Properties & Sizing
| Property | Value (Dry) | Value (Conditioned) |
|---|---|---|
| Density | 1.14 g/cm³ | — |
| Tensile Strength (yield) | 82 MPa | 55 MPa (50% RH) |
| Elongation at Break | 15–40% | 50–100% |
| Flexural Modulus | 2.8 GPa | 1.2 GPa |
| Impact Strength (Izod notched) | 5.3 kJ/m² | 11 kJ/m² |
| Melting Point | 265°C | |
| Continuous Service Temperature | 80–120°C (mechanical load dependent) | |
| Moisture Absorption | 2.5% (50% RH equilibrium) | 8.5% (saturation in water) |
| CLTE | 80 × 10⁻⁶ /°C | |
| Flammability Rating | UL94 HB (1.6 mm thickness) | |
Canadian Standard Stock Sizes: Sheets 4' × 8' (1220 × 2440 mm) in thicknesses ⅛", ¼", ⅜", ½", ¾", 1"; Rods ¼" to 6" diameter × 6' lengths; Tubes and custom extrusions available.
Tolerances: Sheet thickness ±0.005" up to ½", ±0.010" above; Rod diameter ±0.002" up to 1", ±0.005" above.
Machinability, Tooling & Feeds
Nylon 6/6 machines well with standard HSS or carbide tooling. Use sharp tools with positive rake angles to minimize heat buildup and work hardening.
| Parameter | Carbide | HSS |
|---|---|---|
| Cutting Speed (turning/milling) | 150–300 m/min | 60–120 m/min |
| Feed Rate | 0.1–0.3 mm/rev | |
| Depth of Cut | Up to 3 mm | |
| Drill Point Angle | 118° (peck cycle recommended) | |
| Coolant | Optional; flood coolant (water-soluble) improves finish and accuracy | |
Avoid excessive clamping force to prevent distortion. Post-machining, parts may require drying (e.g., 2 hours at 80°C) to remove absorbed moisture if tight tolerances are needed.
Common Defects & Quality Control
| Defect | Description / QC Check |
|---|---|
| Moisture-induced warpage or dimensional change | Parts can swell up to 0.5% after machining if not conditioned. Verify moisture content ≤ 0.2% by weight for precision parts. |
| Surface crazing | Thermal stress from overheating. Inspect under bright light or with dye penetrant. |
| Voids or porosity | Occurs in extruded rod/plate (especially larger diameters). Reject if visible delamination or >0.1% thickness variation across a 4' sheet. |
| Discoloration | From overheating during machining. Check dimensions after 24-hour conditioning at 23°C / 50% RH. |
Storage, Handling & Racking Guidelines
Store Nylon 6/6 in a cool, dry environment (ideally 20–25°C, <50% RH) away from direct sunlight and UV sources. Keep material sealed in original packaging or polyethylene bags to minimize moisture absorption. Rack sheets vertically on edge in A-frame racks to prevent bowing; support rods horizontally on padded cradles every 2 feet. Avoid stacking heavy loads on top of sheets. Use clean gloves when handling to prevent oil contamination. For long-term storage (>6 months), consider vacuum-sealing or using desiccant packs. Rotate stock FIFO to avoid age-related embrittlement.