Depending on the thickness of the treated layer, there are two types of anodizing.
- Thin anodic oxidation: involves an oxide layer 5 μm to 25 μm thick and is usually a surface protection and aesthetic finishing treatment.
- Thick anodizing: involves a thicker oxide layer, between 13 and 150 μm. Hard anodizing is able to give better mechanical properties to the material, such as resistance to wear, corrosion and the ability to retain lubricants and PTFE coatings.
The thickness of the oxide layer depends on a number of factors such as treatment time and current intensity, which, when properly balanced, can produce different results.
Parameters such as roughness by means of a roughness meter, thickness by means of a magnetic micrometer, hardness by means of a micro-hardness meter and fastening quality by means of a drop test can be entered in ad hoc test certificates drawn up according to the specific requirements of the parts being processed.