Hard Anodizing, also known as Hard Anodic Oxidation Treatment. The typical thickness requirement for hard anodizing films is 25-150 micrometers, with most films ranging from 50-80 micrometers. Hard anodizing films with a thickness less than 25 micrometers are used for parts in applications such as gear keys and helical components, where wear resistance or insulation is required, with an anodizing film thickness of approximately 50 micrometers.