Above is an example of hand metal polishing using a wheel with an abrasive belt.

Polishing, buffing and burnishing can all be categorized as a type of mechanical metal finishing. Mechanical finishes are applied by physical abrasion of the metal surface using a secondary media. The media can vary greatly and includes cloth, stone, metal and plastics combined with finishing compounds to aid the process. Methods of application include wheel abrasion, blasting, tumbling barrels and vibratory finishers.

Mechanical type finishes can be classified into three basic categories by the way the parts to be finished are handled:

• Individually handled and finished using wheel abrasion
• Mass finishing using tumbling barrels or vibratory finishers
• Power blasting

The highest quality mechanical metal finishes are usually obtained by individually handling the parts and using some type of wheel abrasion. Fine hardware, furniture, and motorcycle parts are typically finished using this method. These finishes include:

• Grinding - Used to remove large amounts of metal, grinding can be used to remove large burrs (deburring), heavy scale, rust, and major metal imperfections. The resulting finish has significant grit lines and needs additional mechanical finishing prior to electroplating.
• Polishing - Very often mistaken as a mirror bright finish, polishing is similar to grinding but uses finer grits and compounds to remove significant metal imperfections and small metal burrs. It is usually used prior to buffing in order to obtain a mirror bright finish. In some cases multiple polishing steps using progressively finer grits are needed to obtain the desired finish.
• Buffing - Using cloth wheels combined with compounds, buffing is a final mechanical finish that results in a mirror bright to near mirror bright finish, depending upon the base metal and/or prior mechanical finishing steps. Buffing does not remove a large amount of metal and, therefore, is sometimes applied after a plating process (for example, a dual finishing process, such as after copper plating prior to nickel plating).
• Satin - Also a final mechanical finish, a satin finish is an even, fine-grain, brush-type finish. A fine grit polishing finish produces a finish similar to a satin. This finish is also used as part of the antique processing of larger parts and is often done after the plating process.

Mass mechanical finishing usually referred to as burnishing is a cost effective way to remove burrs and brighten metal where a perfect mirror finish is not required. A wide variety of methods exist using different types of machinery, media, and compounds depending upon the base metal and the desired results. Burnishing is also often used for brightening parts after the plating process, such as brass plating small parts or antique finishes on small parts.

Power blasting is not very common as pre-treatment to an electroplated finish. It is sometimes used to remove heavy scale or if the desired final finish is to be matte.