I am trying to gather information regarding mechanical polishing stainless steel.
We manufacture vessels and have a company standard set at 20 Ra. On occasion we get special customer requests for 15 Ra.
Our shop typically goes overboard and finishes to 5 - 10 Ra (to get a pretty finish), that extra work is expensive.
Marketing requires a pretty finish.
I am trying to develop a method to get us to an affordable and acceptable finish. My plan is to machine or mechanically polish to set finish then electropolish to clean and improve the appearance.
I am trying to find a source of information that will cross reference; industry standard finishes i.e. #2B, #4, #6, Buffed #7 etc., grit 150, 180, 240, 320 etc., ISO Designations, Ra Micro inch and Ra micron. I have collected various pieces and have collated them into a spread sheet, but still have some holes and want to double check it against some reference, as well as add to it.
Do you have any suggestions where I can go to get this information.
You should be able to get approximately 50% reduction in Ra after electropolishing properly finished stainless steel sheet. In other words, if you need a 15 Ra, you should be able to get there from a 25-30 microinch finish.
The process for mechanical finishing prior to electropolishing is substantially different than the one used to produce the standard mill finishes. The details are too lengthy for E-mail, please contact us for further information.Ed Bayha
Metal Coating Process Corporation - Charlotte, North Carolina
I have successfully removed scratches from mirror finish stainless steel inside passenger lifts to the extent that only a bloom was visible afterwards. It took hours of hard work with successively finer grades of emery paper. Does anyone know a quicker way to do the job on-site?
Yours faithfullyJohn Venning
You can use a Dremmel or similar hand held power tool, instead of rubbing by hand. And I would suggest buffing wheels and polishing compounds rather than dry polishing. Our Directory of Chemicals lists several suppliers of wheels and compounds. But basically you have it right: there's no easy way, you have to successively use finer grade polishing media.
Ted Mooney, P.E.
Pine Beach, New Jersey
We manufacture marine fittings and accessories.
It often happens that clients like stainless steel products to be finished in a Mirror effect.
Sadly I could not find someone in S.A. that could give me more information about polishing stainless steel. If you have some information that could bring us closer to solving our problem I would appreciate your reply.
Cape Town South Africa
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