ELECTROPOLISHING

GENERAL
Electropolishing is a process by witch metal is cleaned and polished in a special electro-chemical solution. An electric current passes through a chemical bath dissolving a small amount of a smear metal from the surface of the part, thus leaving a smooth, shiny finish. During the process, the current
density is greatest on the outside corners and edges of the part, so those areas are made especially smooth.

The difference between electropolishing and plating is that instead of adding a coating of metal to a part, electropolishing removes metal from the part’s surface.

The process of electropolishing has proved useful on a wide variety of metals, principally stainless steel, brass, aluminum and copper. Other high grade steels also respond well to the process.

PHYSICAL APPEARANCE IMPROVED
Electropolishing’s chief function is to improve parts cosmetically. It cleans, polished and brightens stainless steel in a way that no other process can. The results are easily visible to the naked eye when comparing parts before and after electropolishing.

Another big advantage of electropolishing is that it removes small burrs from the surface of a part. Because there is no vibration or tumbling involved, as in mass deburring, there is no chance for damage to the parts. Electropolishing makes extra finishing operations unnecessary so the price per part is kept lower.

CORROSION PROTECTION
Although stainless steel is known primarily for its excellent resistance to corrosion, it will still corrode under conditions where impurities are left on the surface of the metal. Electropolishing helps eliminate this problem by dissolving a minute layer of metal from the part’s surface. The surface is left brighter, passivated and protected from rust.

OTHER APPLICATIONS
Electropolishing is not right for every part. Consultation with one of the engineers should precede any new application.

There are some parts such as food processing and handling equipment which are especially suited for electropolishing and its advantages. Electropolishing removes harmful impurities from the surfaces of such parts.

Spring’s and delicate stampings, because they are subjected to repeated stress. Have a tendency to crack or wear out prematurely. Electropolishing helps to protect the lives of these parts by removing surface defects which contribute to part failure.

Gears and splines often grow during heat treating and electropolishing reduces them to their original size, thus salvaging the parts.

Parts requiring better micro finishes, especially intricate parts, have their surfaces greatly improved through electropolishing. As a result, friction, leakage and wear problems are eliminated.

ADVANTAGES OVER OTHER FINISHING METHODS
Other finishing and polishing methods present problems for some parts, especially those that are extremely delicate or difficult to polish. Such parts tend to get caught on polishing and buffing wells, often resulting in bending or breakage.

REASONS TO SPECIFY ELECTROPOLISHING

• Brightens, cleans and polishes metal surfaces
• Removes fine burrs without damaging parts
• Removes smear metal from part surfaces
• Reduces minute scratches and imperfections
• Removes impurities which can cause corrosion in stainless steel
• Improves micro finish surfaces on intricate parts
• Smooths parts so that their mating part will wear better
• Uncovers hidden defects
• Removes surface defects which can cause springs and delicate stampings to fail prematurely
• Reduces oversized gears and splines so that they meet their original tolerances