1. The Impact of Surface Treatment on Dimensional Tolerances

One of the most overlooked aspects of precision machining is the dimensional growth caused by surface coatings. If your part requires a ±0.01mm tolerance, the finishing process can make or break the final assembly.

• Anodizing (Type II & III): While Type II adds a thin layer (approx. 5-20μm), Hardcoat Anodizing (Type III) can add up to 50μm. Designers must account for this "build-up" in their CAD files.

• Electroless Nickel Plating: This provides an incredibly uniform coating even on complex internal geometries, with thickness control as precise as ±2μm.

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2. Common Finishing Options & Their Functional Benefits

Anodizing (Aluminum Alloys)

Ideal for 6061 or 7075 aluminum, anodizing creates a non-conductive, ceramic-like surface. It is the gold standard for parts requiring both color and wear resistance.

Passivation (Stainless Steel)

Crucial for the 300 and 400 series stainless steel. Passivation removes free iron from the surface, maximizing the natural corrosion resistance of the material without changing its dimensions. This is mandatory for medical-grade components.

Bead Blasting & Polishing

For parts where aesthetics or flow dynamics matter, bead blasting provides a uniform matte finish, hiding tool marks (CNC lines). Mechanical polishing can achieve a mirror-like Ra < 0.1&mu;m finish for high-vacuum applications.

3. Decision Matrix: Choosing the Right Treatment

Use the table below to quickly identify which treatment suits your project requirements:

4. Why Partner with Zhuoguan Metal for Your Finishing Needs?

We provide a One-Stop Solution. Instead of managing multiple vendors for machining and finishing, Zhuoguan Metal takes full responsibility for the final output.

• In-house Metrology: We verify dimensions *after* finishing to ensure your parts are "Ready-to-Assemble."

• ASTM Compliance: All treatments are performed according to international standards (e.g., MIL-A-8625 for Anodizing).

• Custom Masking: If certain areas of your part must remain conductive or within tight tolerances, we provide precision masking services.