POM
Low friction, high stiffness, and good dimensional stability depending on part design and operating conditions.
Materials for CNC Machining
Explore commonly used metals and engineering plastics for precision CNC machining. Each material has unique properties, machining considerations, and surface finishing options. Click on any material below to view detailed specifications and guidance for your project.
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Material Categories
Metals
Aluminum
Lightweight material commonly selected for machinability and structural applications.
Stainless Steel
Corrosion-resistant, durable, clean finish.
Carbon Steel
Commonly selected for strength, durability, and cost-sensitive mechanical components.
Copper & Brass
Electrical and thermal efficiency, with good machinability in suitable brass grades.
Titanium
High strength-to-weight material for demanding engineering requirements.
Material Performance & Machining Matrix
Aluminum
- Machinability
- High
- Relative strength
- Medium
- Tool wear
- Low
depending on alloy
- Cutting behavior
- Low cutting force
- Chip formation
- Semi-continuous chips depending on alloy
- Thermal behavior
- Generally good heat dissipation
- Process sensitivity
- Generally stable
Stainless Steel
- Machinability
- Medium
- Relative strength
- Medium to high
- Tool wear
- Medium to high
depending on grade
- Cutting behavior
- Higher cutting force than aluminum
- Chip formation
- Irregular chips; work-hardening risk
- Thermal behavior
- Heat concentration may occur during machining
- Process sensitivity
- Requires careful process control
Carbon Steel
- Machinability
- Medium
- Relative strength
- Medium to high
- Tool wear
- Medium
depending on grade
- Cutting behavior
- Medium to high cutting force
- Chip formation
- Generally controlled chips
- Thermal behavior
- Varies by grade and cutting conditions
- Process sensitivity
- Medium
Copper
- Machinability
- Low to medium
- Relative strength
- Low to medium
- Tool wear
- Medium to high
depending on grade
due to adhesion
- Cutting behavior
- Low cutting force, with adhesion risk
- Chip formation
- Continuous chips
- Thermal behavior
- High thermal and electrical conductivity
- Process sensitivity
- Requires careful fixturing and tool selection
Brass
- Machinability
- High
- Relative strength
- Low to medium
- Tool wear
- Low
depending on grade
- Cutting behavior
- Low cutting force
- Chip formation
- Short, broken chips
- Thermal behavior
- Moderate thermal behavior
- Process sensitivity
- Generally stable
Titanium
- Machinability
- Low
- Relative strength
- High
- Tool wear
- High
strength-to-weight potential, depending on grade
- Cutting behavior
- Very high cutting force
- Chip formation
- Segmented chips
- Thermal behavior
- Low thermal conductivity; heat concentration risk
- Process sensitivity
- High process sensitivity
This matrix provides general material selection guidance only. Specific machining behavior should be reviewed according to material grade, part geometry, tolerance requirements, surface finish, and production requirements.
Machining Force & Cutting Resistance
Aluminum and brass require relatively low cutting force, enabling efficient CNC machining.
Stainless steel and titanium require significantly higher cutting force due to material strength and heat resistance.
Copper exhibits low cutting force but introduces adhesion-related machining challenges.
Chip Formation Behavior
Aluminum typically produces long or semi-continuous chips depending on alloy composition.
Stainless steel generates irregular chips due to work-hardening behavior.
Brass generally provides stable chip-breaking characteristics compared with many other commonly machined metals.
Copper produces continuous chips with high adhesion risk.
Titanium forms segmented chips with high tool stress concentration.
Tool Wear & Thermal Behavior
Titanium and stainless steel generate high tool wear due to heat concentration and abrasion.
Copper causes adhesive wear due to material sticking behavior.
Brass and aluminum maintain low wear and stable tool life under proper conditions.
Machining Stability & Process Sensitivity
Aluminum and brass commonly provide good machining stability when part geometry, tooling, and process requirements are properly reviewed.
Stainless steel and titanium require strict process control and rigid tooling setups.
Copper is sensitive to deformation and requires careful fixturing.
Engineering Plastics
Nylon
Tough and wear-resistant, with chemical resistance depending on material grade and operating environment.
Polycarbonate (PC)
High impact resistance, rigidity, and transparency, with dimensional stability reviewed according to geometry and operating conditions.
PTFE
Excellent chemical resistance and a low-friction surface, with suitability reviewed according to part geometry and application requirements.
Material Selection by Requirement
Not sure which material may be suitable for your project? The following guide provides a general starting point for material selection.
- Need Lightweight Components?
- Consider Aluminum or Titanium.
- Need Corrosion Resistance?
- Consider Stainless Steel, Titanium, or PTFE.
- Need High Strength-to-Weight Ratio?
- Consider Titanium or 7075 Aluminum.
- Need Electrical Conductivity?
- Consider Copper or Brass.
- Need Wear Resistance?
- Review material options based on wear conditions, load, friction, and machining feasibility.
- Need Low Friction Performance?
- Consider POM or PTFE depending on friction requirements, wear conditions, and part design.
- Need High Temperature Resistance?
- Consider Titanium or review suitable material options according to operating conditions.
- Need Cost-Effective General-Purpose Machining?
- Consider Aluminum 6061, Carbon Steel, or POM.
Material Selection Guidance
Choosing the appropriate material involves balancing performance requirements, manufacturing considerations, and project budget.
- Mechanical strength requirements
- Component weight targets
- Corrosion resistance requirements
- Operating temperature conditions
- Wear and friction considerations
- Surface finishing compatibility
- Production volume and cost objectives
Material selection should be evaluated together with machining strategy and finishing requirements to help achieve the desired performance and appearance of the final component.
Surface Finishing Overview
Many CNC machined components benefit from additional finishing processes that improve appearance, corrosion resistance, wear performance, or surface cleanliness.
Common finishing options include:
- Anodizing
- Hardcoat Anodizing
- Chromate Conversion
- Electropolishing
- Passivation
- Powder Coating
- Zinc Plating
- Electroless Nickel
Selecting a material and surface finish together during the design stage can help avoid manufacturing challenges and support desired functional requirements.
View Surface Finishing Options →