Coloring 400 Series Stainless black 1

[craigmj]

Hello Group,

I am looking to color some 400 series stainless steel parts black. I would prefer not to paint because the end use of the product will be harsh and the paint will scratch off. I want the coloring to be consistant (is a consumer product) and durable.

Does anyone have ideas?

Thank you
CJ

 

[swall]

You need to supply more information about the product application and the operating environment. You must have chosen stainless for a reason, and some potential blackening methods could enhance or hinder the stainless properties.

 

[kenvlach]

Have it hot black oxided per MIL-DTL-13924D, Class 2, 3 or 4 (depends on process vendor availability and also the heat treatment of your 400 SS). Download the spec. from ASSIST:

http://assist.daps.dla.mil/quicksearch/

(just paste 13924 in the Document Number box & Submit). Deep link:

http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=10340

 

[craigmj]

OK sorry.

SS needs to be magnetic (thats why 400 series) and moderately corrosion resistant. The use is a tool body.
Op temp: -30C - 60C; outdoor use
I would like the post process finish to be matte and not oily (it will be handled by customers on a daily basis). Its very important that the oxide (or whatever) looks good, meaning consistant color from lot to lot.

Is that a little better?
thanks
CJ


btw...kenvlach - thanks for the link!

 

[kenvlach]

For a non-oily surface, specify a 'dry touch' wax (a water-displacing oil is the default). For longer life, go to clear polyurethane topcoat. See 'Rust Preventatives' at

http://www.birchwoodcasey.com/rust/index.html

http://www.heatbath.com/Products-link-page.htm

[LHS product menu]
or 'Corrosion Preventatives' at

http://www.hubbardhall.com/hbhall/pages/metalchild.jsp?id=82

Some black oxiders don't perform black oxide on stainless or have dry touch finish available. Here's one that does:

http://www.blackoxideservice.com/

 

[tripleZ]

Black PVC coating maybe. IonBond does this to one of my parts. You can still see the imperfections in the base material once applied. It shouldn't affect the magnetic properties, but you'd be better talking to one of their applications folks about that one.