Generally, the steel blackening (black oxidation) treatment can effectively improve the corrosion resistance, but the protective effect is still quite limited. Oil immersion or subsequent rust prevention treatment is still required to really improve the corrosion resistance and lubricity of the blackened layer.

Anodizing is a process of surface treatment. The final process of metal manufacturing is surface finishing, anodizing precision machined metal parts, a reliable and relatively inexpensive method to improve wear resistance and coloring aluminum and other non-ferrous metals.