Bluing is a superficial oxidation of ferrous components that gives iron and carbon steel parts a glossy black color.
This surface treatment does not in any way affect the dimensions of the part, as it does not involve any thickness build-up. Its value is mainly aesthetic, as it gives the piece a very pleasing appearance.
The treatment can be carried out in a tumbling or static process, depending on the shape of the parts and/or the customer’s needs, and takes place at a temperature of about 140 degrees in immersion in an alkaline-based solution.