Metal pickling is a process that is used to treat metal surfaces. It serves to remove impurities from the metal, including stains, rust, scale, and inorganic contaminants.

The use of high temperatures in metal working processing is common, but such processes can leave layers of oxidation on the surface of the material, which leads to staining and scaling. Metal pickling is used to remove these blemishes. To restore the best corrosion-resistant performance, the damaged metal layer must be removed, exposing a fully alloyed surface. The steel is dipped into a vat of the pickle liquor, and the acidity dissolves the stain.

Pickling removes embedded iron, weld scale, surface iron contamination, and heat tint from the material.