Class I and Class II Anodize – What is the Difference?

Class I and Class II anodic coatings are designations created by the Aluminum Association for the purpose of codifying the specification of anodized aluminum.

Class I coating has a mil thickness of 0.7 (18 microns) or greater

Class II coating has a minimum mil thickness of 0.4 (10 microns)

Class I coating is a high performance anodic finish used primarily for exterior building products and other products that must withstand continuous outdoor exposure.

Class II coating is a commercial anodic finish recommended for interior applications or light exterior applications receiving regularly scheduled cleaning and maintenance such as storefronts.

Class I and Class II coatings should not be confused with Type I, Type II, and Type III anodic coatings as described in the authoritative anodizing standard, MIL-A-8625. Type I anodize refers to chromic acid anodizing. Type II is normal “clear” sulfuric acid anodizing. Type III is “hardcoat” using sulfuric acid or mixed chemistry electrolytes.

All Linetec anodize finishes are produced as a Class I coating, with the exception of ANO-204 Clear, which is a Class II coating. Clear anodize is available in both Class I and Class II.

Class II Anodize -McDonaldsClass II anodic coatings are recommended for interior applications or light exterior applications receiving regularly scheduled cleaning and maintenance such as storefronts and entrance ways. Class II anodize is not as durable or wear resistant as a Class I finish.

 

Adelson School 7Class I anodic coating is a high-performance finish used for exterior building structures and other products that must withstand continuous outdoor exposure. Class I anodize is more resistant to salt spray and the sea coast, and it is more durable in high traffic areas.

Linetec explains Class I and Class II Anodize

Anodize-TCCherryAirport09Class I and Class II anodic coatings are designations created by the Aluminum Association for the purpose of codifying the specification of anodized aluminum.

The AAMA 611 specifications and warranty involves both Class I  and Class II  anodize.

Class I Anodize coatings have a mil thickness of 0.7 (18 microns) or greater.

Class II Anodize coatings have a minimum mil thickness of 0.4 (10 microns).

Class I coating is a high performance anodic finish used primarily for exterior building products and other products that must withstand continuous outdoor exposure.

Class II coating is a commercial anodic finish recommended for interior applications or light exterior applications receiving regularly scheduled cleaning and maintenance such as storefronts.

Linetec’s documented testing allow us to offer warranties of five (5) years, on Class I Anodize finishing, with confidence that your product will perform as intended. With prior approval and a minimal up-charge, Linetec can offer an extended warranty up to ten (10) years on Class I Anodize.

The anodizing warranty for Class I, (0.7 mil) clear, bronze and black finishes is backed by the strength of Linetec. We warrant that the finish will not chip, crack, or peel (adhesion), chalk, or color change/fade.

Class II clear anodize, with the minimum mil thickness of 0.4 is not offered with a warranty

Class I and Class II coatings should not be confused with Type I, Type II, and Type III anodic coatings as described in the authoritative anodizing standard, MIL-A-8625. Type I anodize refers to chromic acid anodizing. Type II is normal “clear” sulfuric acid anodizing. Type III is “hardcoat” using sulfuric acid or mixed chemistry electrolytes.

All Linetec anodize finishes are a Class I coating, with the exception of ANO-204 Clear, which is a Class II coating.