TYPE I ANODIZING

Also known as Chromic Acid Anodizing, this is the oldest anodizing process. Chromic acid anodizing is mostly used for protection of critical structures with all kinds of joints. The corrosion resistance is excellent relative to the thickness of the coating. The main use of Chromic Acid Anodizing is due to the fact that residues from the chromic acid trapped in parts that are difficult to rinse does not lead to corrosion. Another important feature is the fact that Type I coatings keep the aluminum materials fatigue strength and the very thin layer makes a minimal dimensional change. Parts treated with this process are harder to dye and is generally applied as a pretreatment before painting.