Chemical
Film
Chemical conversion, chem film, alodine, iridite, and chromating are different names for the same process. It is used to allow an aluminum part to maintain electrical conductivity, enhance corrosion resistance, and/or prepare it for painting.
MIL-C-5541
Class 1A – For maximum corrosion protection on painted or unpainted surfaces.
Class 3 – For corrosion protection where low electrical resistance is required.
No dimensional changes.
Gold or clear, as specified.
Primarily used as a base for paint to enhance adhesion. It offers good corrosion resistance and electrical conductivity.
It should be specified whether a gold or clear finish is desired.
CLASS 3: This coating is mainly used for low electrical resistance contacts and has lower corrosion resistance compared to CLASS 1A.