Surface finish
Alodine is a chemical conversion coating for aluminium and magnesium. It adds corrosion resistance and a base for paint without changing dimensions.
What it is
Alodine (also called chem film or chromate conversion coating) is a chemical surface treatment. The metal is dipped in a bath that reacts with the surface. This forms a thin, integral oxide layer. It is not a paint, so it cannot peel. Alodine meets MIL-DTL-5541 and is widely used in aerospace and electronics.
How it works
Clean & degrease
We remove oil, dirt, and old oxide so the coating is even.
Rinse
A clean water rinse prepares the surface for the chemical bath.
Alodine bath
The part soaks in the chromate solution. A reaction grows the conversion layer.
Final rinse & dry
We rinse and dry the part. No extra seal is needed.
Why choose it
Protects aluminium and magnesium from rust and salt spray.
Works as a primer so paint and glue bond better.
The coating stays electrically conductive for grounding.
Adds only microns, so fits and tolerances hold.
Simple dip process with short lead times.
We offer hexavalent-free (RoHS) chem film.
Typical specs
| Specification | Typical range / value | Notes |
|---|---|---|
| Standard | MIL-DTL-5541 Class 1A / Class 3 | |
| Coating thickness | 0.5 – 4 µm | |
| Color | Iridescent yellow, clear, or gold | |
| Electrical contact | Conductive (Class 3 for low resistance) | |
| Base materials | Aluminium alloys, magnesium |
Best applications
Lightweight structural parts that need corrosion protection.
Conductive cases for electronics grounding.
Primer layer before powder or liquid paint.
Bonded aluminium housings and panels.
Screws and fittings that need rust protection.
Materials
We apply Alodine to the materials below. Not sure if your material qualifies? Our engineers will confirm it for free.
Our solution
We run Alodine (chem film) in-house to MIL-DTL-5541. We help you pick Class 1A for max protection or Class 3 when you need low electrical resistance.
Design tips
Tell us which threads or holes to leave bare.
The film shows an iridescent yellow to gold tint.
Use Alodine as a primer if you will paint later.
Oil on the surface stops the chemical reaction.
FAQ