What Materials Can Be Used in Low Volume CNC Machining?

Low volume CNC machining is a cost-effective solution for producing precision parts in smaller batches (typically 10–1,000 units). Material selection plays a critical role in balancing performance, machinability, and budget. Below, we explore the most suitable materials for low volume CNC projects and their unique advantages.

1. Metals: The Go-To Choice for Durability

Metals dominate low volume CNC machining due to their strength, thermal stability, and wide availability.

Aluminum (e.g., 6061, 7075)

• Why it’s ideal:

• High strength-to-weight ratio, corrosion resistance, and excellent machinability reduce cycle times.

• Cost-effective for prototypes and functional parts like brackets or housings.

• Low volume tip: Anodizing enhances aesthetics and durability without significant cost increases.

Stainless Steel (e.g., 304, 316)

• Why it’s ideal:

• Resists corrosion and extreme temperatures, ideal for medical or marine applications.

• Slower machining speeds compared to aluminum, but small batches offset tooling costs.

• Low volume tip: Opt for 303 stainless for improved machinability in complex geometries.

Titanium (Grade 2, Grade 5)

• Why it’s ideal:

• Biocompatible and lightweight, perfect for aerospace or medical implants.

• Challenging to machine but viable for high-value, low volume parts.

• Low volume tip: Partner with shops experienced in titanium to minimize scrap rates.

  
  

2. Plastics: Lightweight & Versatile

Engineering plastics are popular for electrical insulation, reduced weight, and chemical resistance.

ABS

• Why it’s ideal:

• Easy to machine and paint, suitable for consumer product prototypes.

• Low material cost balances higher machining time for small batches.

PEEK

• Why it’s ideal:

• High-temperature resistance (up to 250°C) for automotive or oil/gas components.

• Expensive raw material but justified for critical low volume applications.

Nylon (PA6, PA66)

• Why it’s ideal:

• Wear-resistant gears or bushings benefit from nylon’s self-lubricating properties.

• Moisture absorption requires post-processing for dimensional stability.

3. Composites & Exotics: Niche Performance

For specialized needs, composites and exotic materials offer unique properties.

• Carbon Fiber Reinforced Polymers (CFRP):

• High stiffness-to-weight ratio for drones or robotics.

• Requires diamond-coated tools to minimize delamination in small batches.

• Brass:

• Decorative finishes or electrical connectors leverage its conductivity and polishability.

4. Material Selection Factors for Low Volume Projects

• Lead Time: Aluminum and ABS are widely available, reducing procurement delays.

• Design Complexity: Soft materials (e.g., aluminum) tolerate intricate features better in small batches.

• Post-Processing: Electroplating or heat treatment costs add up; simplify finishes for cost control.

Conclusion

From aluminum for rapid prototyping to PEEK for high-stress environments, material choice in low volume CNC machining hinges on balancing performance, machinability, and budget. Work with your machining partner to optimize designs for your selected material, ensuring efficient production without compromising quality.