What are the common surface finishing options after 3 Axis CNC Milling?

What Are the Common Surface Finishing Options After 3 Axis CNC Milling?

Importance of Surface Finishing in CNC Milling

After 3 Axis CNC milling, surface finishing is critical to improve aesthetics, corrosion resistance, wear performance, and part functionality. The choice of finish depends on the material type, end-use environment, and industry requirements such as aerospace, medical, or consumer electronics.

Common Surface Finishing Options

1. As-Machined Finish

This default finish retains visible tool paths with Ra values around 3.2 µm. It’s ideal for prototypes or internal features where appearance and corrosion resistance are not critical. Learn more

2. Anodizing

Used primarily for aluminum alloys like 6061, this electrochemical process increases corrosion resistance and allows for color finishes. Type II provides decorative coatings; Type III (hardcoat) enhances surface hardness up to 60 HRC. View details

3. Powder Coating

A robust polymer finish applied electrostatically and cured under heat. Suitable for steel and aluminum parts needing high impact resistance, uniform coverage, and a matte or glossy look. Explore more

4. Electropolishing

A precision process for stainless steels like SUS316L that removes microscopic peaks to enhance smoothness and corrosion resistance. Ra values below 0.2 µm can be achieved. Full article

5. Plating (Electroplating / PVD / Chrome)

Includes nickel, zinc, gold, and chrome plating for improved surface conductivity, corrosion resistance, or decorative appearance. PVD coating offers high hardness (2000–3000 HV) for aerospace and tool components.

6. Passivation

Removes iron contamination from stainless steel surfaces, improving corrosion resistance without altering dimensions. Widely used for medical and food-grade components. Read more

7. Sandblasting & Brushing

Mechanical finishes for matte texture or linear grain effects. Sandblasting creates uniform roughness (Ra 1.6–3.2 µm); brushing gives a directional satin look. More info

8. Tumbling & Deburring

Applied to small and medium-sized parts for edge rounding and smoothness improvement. Particularly useful for batch-processed aluminum, brass, and plastic parts. Details here

Surface Finish Selection by Material

End-to-End CNC Machining and Finishing Services

Neway Machining offers full-service solutions from 3 Axis CNC Milling to a wide range of Surface Finishing Processes. Whether you need Anodizing for aluminum components or Electropolishing for stainless steel medical parts, we ensure consistent surface quality and performance for prototyping or production-scale needs.