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Guidance for bright finishing of SS parts

Q. We manufacture small SS components, sheared from Sheet. Size 11 mm x 25 mm x 2.5 mm. To get a bright finish we first BUFF the sheet and then shear it to small components. Thereafter we have to remove the burrs produced by shearing. We wish to avoid the Buffing of the sheet. We can tumble the parts to (a) remove the burrs and(b) get a bright finish. (a) has already been achieved in a tumbling barrel with abrasive materials such as steel balls and stone chips. For (b) i.e. bright finish we are not satisfied.

Can anyone guide us for tumbling the components with some particular material/chemical to achieve this?

Thanks,

Rustom Gandhi
- Allahabad, U.P., India
 

A. There are a couple of things you can do; however, I think you best option is not to buff your metal before you mass finish it with steel balls. This burnishing process will take a longer time cycle to achieve the same results you got before. You may still need to use ceramic deburring media as a first step, if the metal has a very rough surface profile, but try it by itself first. Do not mix ceramic and steel media.

AF Kenton
retired business owner - Hatboro, Pennsylvania
 

A. 2.5 mm is too thick for BA finish so 2B SS sheets could be used to be mirror polished both sided. Protective laser cutting PE films should be used to protect the polished surface before laser cutting (leave no burrs... laser entry and exit point might have to hand deburred). Laser should be set to make two passes, first to cut the PE films and second to cut the SS.

For some applications, it is better and cheaper than chrome plating.

Good luck.

Michael Liu Taylor
specialty stainless steel distributor - Dallas, Texas
 

A. I suggest that you try emery grains available in the market. They are cheap and impart a very good shine also. You can use 36, 40 or 50 grit nos. if the deburring required is small in dimension. Fine tuning can be achieved by trial and error. Finer emery powder e.g. #400 or calcined alumina #400 in a separate tumbling operation should give you a mirror like finish. These materials are very cheap compared to the ceramic and steel media.

Mahavir Mahedu
- Jamnagar, Gujrat, India