Hot rolled pickled and oiled (P&O) is a product with an enhanced surface finish due to the pickling process. The process of creating hot rolled P&O begins with basic hot rolled steel.
To create the enhanced surface finish of hot rolled P&O the hot rolled goes through a pickling process. The pickling process removes the thin layer of oxidized iron (black oxide scale) that forms on the surface of the steel. This is done using acid baths. Once the acid is rinsed and the product is dried oil is applied to prevent the steel from rusting.