Specializing in Conversion Coatings

ChemfilmChromate Conversion Coatings

Chemfilm Aluminum Coating

Using Tri-valent Chrome

Chemfilm – hex chrome free and meets ELV, RoHS and WEEE initiatives.

Chemfilm, or chromate, is a conversion coating of aluminum using the base material to create a very thin film on the surface of the part. The coating thickness is near unmeasurable and will not create any dimensional change of the work piece.

Chemfilm Class 3 alone will give moderate corrosion resistance to parts while maintaining a low electrical resistance. Class 1A will give a slightly thicker coating for increased corrosion protection but with a higher electrical resistance.

Chemfilm can be used as a stand alone coating, under paint or in combination with anodizing to create electrical contact areas.

Offering Selection

Clear Anodizing
Black Anodizing
SS Passivation
Material used on
Stainless Steel
Coating thickness
0.2 – 0.8 mil
0.6 – 1.2 mil
0 – not measurable
0 – no coating buildup
Dimensional increase
~50% of coating thickness
~50% of coating thickness
Electrical conductivity
None, insulator
None, insulator
Type 3 – very good; Type 1A – good
No change from base material
MIL-A-8625F type II class 1
MIL-A-8625F type II class 2 (black)
MIL-DTL-5541 type II, class 1A and 3
AMS2700 method 2, ASTM-A967 citric 2
Gloss silver to matte silver
Medium gloss black to matte black
Slight yellow to blue tint to base material. Some light streaking possible
No change to base material – SS appearance
Corrosion resistance
Very good – 336 hour salt spray
Very good – 336 hour salt spray
Good – 100 hour salt spray
Excellent – no salt spray corrosion
ELV/WEE compliant
Cost of process
Max part size at WFL
30″ x 30″ x 48″
30″ x 30″ x 48″
30″ x 40″ x 108″
< 5" - bulk barrel

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