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Reducing the variation of hardchrome plating

Sir,
How can we reduce the variation of hardchrome plating on ss 410 (min35 mic-observed is 38 -60 mic on the same piece)?
Will excess Run out be caused due to hard chrome plating process?
Set up in the bath that is the anode , cathode position, bath tub size , electricity passed , Salt used, would have an effect on the hard chrome formed?

Abhilash Peethambar
Researcher - Coimbatore, India
December 29, 2008

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Hi, Abhilash. Whether this thickness variation will cause "excess run out" is an engineering question rather than a finishing question, and we don't even know what kind of component you are speaking of. So I can't help you there.

But yes, every parameter you mentioned will affect the plating thickness variations. To understand them all, you might need a book on the subject like Guffie's "Hard Chromium Plating" -- please see if a library or co-worker has a copy.

Still, the thing that has the most effect on plating thickness variations for hard chrome plating is the closeness of the anodes to the cathodes. Often it will take very careful fixturing, including thieves, to reduce thickness variations. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
December 29, 2008

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Dear Abhilash
As you are saying your variation is very high ,if this variation is in circular line( as you said about run out) of roller it means your component (cathode) is not in centre of anode. It should be in centre And If This variation is in longitudinal direction then you have to check your anode, its overall length should not be more then cathode's length.

AMIT RAI
- Kanpur, U.P., India
April 16, 2009