Pickling is basically the cleaning of steel using an acid of some type, typically hydrochloric acid. When a hot rolled coil cools, rust forms on the unprotected metal and when coils are transported or stored they are exposed to air and water. Pickling removes the rust, dirt and oil from the surface. Leveling is a process to flatten shape deficiencies such as wavy edges and buckles in a sheet of steel. Cold finishing is processing done to hot rolled bars in the cold state to improve the surface finish, dimensional accuracy, machinability or mechanical properties.
Cold drawing gives the bar a bright, clean, uniform surface and increases the strength.
Turned and polished bars have the surface layer removed, are rotated through rollers that staighten and polish the bar and are cut to length. Ground and polished bars are cold drawn or turned bars ground to close tolerances and kept very straight. They are polished to a brilliant, bright finish, resulting in bars with extremely close size tolerance, a high degree of straightness and a superior finish. Tempering is a carefully controlled cold rolling process that improves the flatness, produces the final finish or texture and develops the required mechanical properties.