Electropolishing of Stainless Steel

Praj Hipurity |

Topic Covered: Electropolishing (History, Know How, Effects & Application)

As we are part of the Pharma & Biotech Industry we often refer to electropolishing in our day to day discussions for equipment & components used in the systems used for handling, storage, transporting & distribution of critical products.

This Blog is aimed to provide the readership with insightful understanding of the electropolishing process, its fundamentals and its application.

History of Electropolishing

In 1912 when Imperial German Government issued a patent for finishing of silver in a cyanide solution, electropolishing process was invented.

Lots of efforts were put in the years to come but it was year 1936/37 when Dr, Charles Faust and his team discovered solutions for electropolishing Stainless and other metals.

So What is Electropolishing?

Electropolishing is the electrochemical process to remove the metallic material from the workpiece, in order to obtain a smoother metal surface; it basically streamlines the microscopic surface of a metal object. If defined in simple words its reverse of plating.

So why Electropolishing is done?

In addition to design and the choice of material, the quality of surface finish has a decisive effect on the function & performance of the component service life and effectiveness.

The treatment of metal surface therefore determines the suitability, performance and the operating cost.

What are the effects of Electropolishing on Metal?

Basically there are two types of Effects, Macroscopic & Microscopic.

Macroscopic Effect: As the electropolishing process starts, the concentration of electric field at edges and protrusions of the work piece locally creates higher current densities which increases the removal rates which is useful for removing the macroscopic burrs or in simple words we can say fine de-burring of the work piece.

Microscopic Effect: Post the Macroscopic Effects starts the Microscopic effect, In this a thin layer of polishing film is formed at the surface of the work piece , it removes the micro level roughness of the surface of the work piece creating a smooth and polished finish of the surface.


Today electropolishing is successfully applied to an expandable range of new applications. Major benefits of electropolishing is successfully continued to be demonstrated in Reactor vessels, Process Equipment, Bioreactors, Heat Exchangers, Storage Tanks, Piping and Tubing, F & B Processing Equipment, etc.