Chem Film

A chromate conversion coating that protects aluminum from corrosion while keeping the surface electrically conductive.

What is Chem Film?

A chemical conversion coating for aluminum, also known as Alodine or chromate conversion coating, that adds corrosion resistance without insulating the surface the way anodizing does.

How it works

The aluminum part is dipped in or sprayed with a chromate (or trivalent chromium) solution that reacts with the surface to form a thin oxide layer, typically clear or gold depending on the chemistry used. The layer is thin enough to leave tight tolerances unaffected.

Benefits

  • Keeps the surface electrically conductive, unlike anodizing
  • Adds meaningful corrosion resistance for a thin, low-cost layer
  • Thin enough not to affect tight-tolerance features
  • Common base layer under paint or Type II/III anodizing

Applications

Electronics enclosures and EMI-shielding parts that need grounding continuity, aerospace parts specified to MIL-DTL-5541, and as a pretreatment layer before paint or anodizing.

Chem Film example

Applicable Materials & Colors

Aluminum. Full applicable-materials list, color range, and which finishes can combine are confirmed per order — see the Materials & Finishes page →

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