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  for Metal Finishing since 1989
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Etch process to roughen 316 SS for glue adhesion

We want to glue a part into a round through hole in a stainless part using cyanoacrylate adhesive. Our process produces a 10 Ra finish on the hole. We feel the adhesion would be improved if the surface of the hole could be roughened up to 40-60 Ra. I was thinking that an electrochemical etch may provide a roughening effect while not changing the dimensions.

Joe Dille
- Hatfield, Pennsylvania, USA

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The nitric/hydrofluoric pickle done on 316 by steel producing mills usually results in a grain boundary ditching but nothing like the roughness you're describing. Why not simply abrade the surface? 80 grit abrasive would give you that target roughness.

Michael Mcguire
- Pittsburgh