Should you CNC machine your parts from plastic or metal? The answer depends on your application requirements, operating environment, and budget. This comparison helps you make the right choice for your project.
Plastic vs Metal CNC Parts: Key Differences
| Factor | Plastic | Metal |
|---|---|---|
| Weight | Light (1-2 g/cm³) | Heavy (2.7-8 g/cm³) |
| Corrosion Resistance | Excellent | Varies, needs coating |
| Cost | Lower material & machining cost | Higher, especially exotic alloys |
| Thermal Resistance | Up to 340°C (PBI) | Up to 1000°C+ |
| Electrical Insulation | Natural insulator | Conductive |
| Machinability | Easier, faster feed rates | Harder, slower tooling |
| Surface Finish | Smooth as-machined | May need post-processing |
When to Choose CNC Plastic Parts
- Weight reduction is critical (aerospace, automotive)
- Chemical or corrosion resistance required
- Electrical insulation needed (semiconductor, electronics)
- Cost-sensitive high-volume production
- FDA or biocompatibility compliance required
- Low friction / self-lubricating applications
When to Choose CNC Metal Parts
- Extreme temperatures above 340°C
- Very high structural loads
- High wear with abrasive media
- Magnetic properties needed
- High thermal conductivity required
Hybrid Approach: Plastic + Metal
Many applications benefit from combining plastic and metal components. For example, metal inserts in plastic gears, or plastic bushings on metal shafts. Our team can advise on hybrid designs.
Contact our engineers for material selection support. ISO 9001 certified. RFQ response within 24 hours.