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316 stainless steel can't be polished without pits, inclusions or voids

March 2, 2010

The company I work for wants to polish flat 316 Stainless Steel plate components, typically made from 0.5 thick sheet.

The parts are normally sand blasted and we have no problem with that but polishing reveals small inclusions or voids which make the finish cosmetically unacceptable.

Is there a grade of thin sheet 316 Stainless that is polishable?

Martin Johnson
Designer - Fleet, Hants, England

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Not sure if the thickness is 0.5 mm or 0.50" but in either case, T304 or T316 shouldn't be a problem. I suspect the supplying mills is not offering quality material therefore when it is polished, pits and pinholes will show. Sort of like polishing swiss cheese, each layer shows imperfections.

Michael Liu Taylor
specialty stainless steel distributor - Dallas, Texas
March 4, 2010

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Wrong polishing procedures could also develop pits on sound materials. That's another possibility,
Guillermo Marrufo- Monterrey, Mexico

Guillermo Marrufo
Monterrey, NL, Mexico
March 17, 2010

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Notice that you mentioned the parts are "normally blasted". If your parts are flat and full of surface variations, may I suggest that you use a mass finishing system with dry organic media. It slower than blasting, but it is a more uniform treatment with better results.

AF Kenton
retired business owner - Hatboro, Pennsylvania
March 22, 2010