CNC Machining Surface Finishes: Anodizing, Powder Coating, Painting, and Clear Coat Compared

Why Surface Finishes Matter for CNC Machined Parts

When customers order CNC machined parts, they often ask:

• “Which finish should I choose?”

• “Is powder coating stronger than paint?”

• “How can I make aluminum look premium?”

Surface finishing is not just about looks. The right finish can:

• Protect parts from rust and corrosion

• Improve resistance against scratches and daily wear

• Make products look professional and high-quality

• Extend the working life of components

Quick Comparison of Common Finishes

Which Finish Should You Choose?

• Premium aluminum look → Anodizing

• Outdoor protection → Powder coating

• Low-cost prototype → Painting

• Glossy natural metal → Clear coat

Note: Laboratory test results often represent the best-case scenario. Real-world performance depends on environment, UV exposure, and handling conditions.

Real-World Applications

• Electronics → Anodized aluminum cases protect devices and add color options.

• Automotive → Powder-coated CNC steel parts resist rust on brackets and frames.

• Prototypes → Painted samples offer fast turnaround and flexible colors.

• Display Parts → Clear coat preserves the natural shine for indoor products.

Visual tip: Place application photos (e.g., anodized phone housing, powder-coated automotive bracket).

Customer Feedback

“We switched from painted enclosures to powder coating. The finish lasted much longer in outdoor use, and customers immediately noticed the improved quality.”        — Industrial Equipment Manufacturer, Europe

“Bergek CNC suggested anodizing for our aluminum parts. The color finish looked premium and passed our salt-spray testing.”        — Consumer Electronics Supplier, USA

FAQ: Common Customer Questions

Q1: Is powder coating always better than painting?
   Yes, powder coating is usually thicker and more durable. It’s ideal for outdoor and heavy-use parts. Painting is cheaper and faster for small batches or prototypes, but less durable long-term.

Q2: Can all metals be anodized?
   No. Anodizing is an electrochemical process that builds the oxide layer on aluminum. It works well on alloys like 6061/5052, but not on steel or high-silicon die-cast aluminum. For those, plating or passivation is recommended.

Q3: How long does clear coat protection last?
   Clear coat provides only light protection. Indoors, it may last 6–12 months. Outdoors, unless UV-blocking resins are used, protection usually lasts only a few months.

Q4: Which finish is cheapest for prototypes?
   Painting is usually the most budget-friendly option for prototypes or samples, especially when only color appearance matters.

Q5: Can I get custom colors?
   Yes. Both anodizing and powder coating allow a wide range of colors. Painting is also flexible, but may fade faster over time.

Q6: Which finishes are suitable for medical or food-grade CNC parts?
   Electropolishing and stainless steel passivation are commonly used because they create smooth, clean surfaces that are easy to sterilize.

How We Help Customers

At Bergek CNC Machining Service, we guide clients to select the right finish by considering:

• Material of the part (aluminum, steel, stainless steel)

• Application (indoor, outdoor, cosmetic, functional)

• Budget and production volume

👉 All finishes are provided under our ISO 9001 quality system, ensuring consistency and reliability from prototypes to production.

Final Thought

Choosing the right finish makes CNC machined parts more durable, functional, and attractive.