Polycarbonate (PC) vs Nylon (PA6)
Polycarbonate (PC) and Nylon (PA6) are both workhorse engineering thermoplastics, but they win on opposite strengths: PC for clarity and impact resistance, PA6 for wear, friction, and chemical resistance. The right pick hinges on whether your part takes shock loads or sliding loads.
The verdict
Choose Polycarbonate (PC) when you need transparency, high impact resistance, or dimensional stability in wet and humid conditions. Choose Nylon (PA6) when the part slides, wears, or runs as a bearing or gear, and when it sees oils, fuels, or solvents. In short: PC for shock and clarity, PA6 for friction, wear, and chemical exposure.
Side-by-side data
| Property | Polycarbonate (PC) | Nylon (PA6) |
|---|---|---|
| Category | Plastic | Engineering Plastic |
| Density (g/cm³) | 1.2 | 1.14 |
| Tensile strength (MPa) | 65 | 80 |
| Yield strength (MPa) | 62 | 80 |
| Elongation (%) | 110 | 50 |
| Hardness | R118 | R120 |
| Max service temp (°C) | 120 | 110 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 0.2 | 0.25 |
| Typically used for | Impact-resistant & optically clear parts | Gears, bushings & wear parts |
Which should you choose?
Choose Polycarbonate (PC) if…
- You need a transparent part — glazing, guards, lenses, sight windows — since PA6 is opaque.
- The part takes impact or shock loads and must not shatter (machine guarding, housings, helmet shields).
- It runs in humid or wet service and must hold tolerance — PC barely absorbs water.
- You want a part that resists dilute acids and stays dimensionally predictable.
- You can specify a UV-stabilized grade for outdoor exposure to prevent yellowing.
Choose Nylon (PA6) if…
- The part slides or wears — bushings, bearings, gears, cams, wear pads — where PA6's self-lubrication shines.
- It contacts oils, fuels, greases, or solvents that would craze PC under stress.
- You need a lower coefficient of friction against metal without external lubricant.
- Fatigue and cyclic loading matter — PA6 handles repeated flexing well.
- You want a cheaper, easy-to-machine stock for turned and milled mechanical parts.
Key differences that matter
- Impact vs wear: PC dominates on impact toughness and resistance to shattering; PA6 dominates on abrasion, sliding wear, and self-lubrication. This single trade-off drives most decisions.
- Moisture is PA6's weakness: nylon absorbs water, which swells the part, lowers stiffness, and shifts tolerances — PC is far more dimensionally stable in humid or wet service.
- Chemical resistance flips: PA6 resists oils, fuels, and many solvents that craze PC, but PC tolerates dilute acids better while PA6 is attacked by strong acids.
- Optics: only PC is transparent; if you need to see through it or transmit light, nylon is out.
- Friction and cost: PA6 offers a lower coefficient of friction against metal and is generally the cheaper, easier-to-machine bearing material.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is Polycarbonate stronger than Nylon?
It depends on the metric. PC has much higher impact strength and resistance to shattering, while PA6 has comparable tensile strength plus excellent fatigue and wear performance. For shock loads choose PC; for sliding or cyclic loads choose PA6.
Which is cheaper, PC or PA6?
PA6 is generally less expensive per part, especially as cast nylon stock for machined bushings and gears. PC commands a premium for its clarity and impact performance.
Can I machine both?
Yes. PA6 machines easily and is a favorite for turned and milled bearings, though it can absorb moisture from coolant. PC machines well too but is notch-sensitive — sharp internal corners and aggressive feeds cause cracking or stress crazing, so use sharp tooling and anneal to relieve stress.
Which handles moisture and outdoor use better?
PC. Nylon (PA6) absorbs water and swells and softens over time. PC stays dimensionally stable when wet, and UV-stabilized PC grades are standard for outdoor glazing — though unstabilized PC yellows in sunlight.
Which resists oils and chemicals better?
PA6 resists oils, fuels, greases, and many solvents that will craze or crack stressed PC. Conversely, PC tolerates dilute acids better, while strong acids and certain solvents attack nylon.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.