Hot black oxide for steel 3

[KENAT]

I posted a question about zinc plate last week (thread332-229185
) and got some helpful responses however, the Engineer has now decided he wants to use Black Oxide instead.

I believe we want the true ‘hot’ black oxide treatment, with an oil supplementary coating.

I’ve done some Google searches and searches of this site but have some outstanding questions. For a commercial application in the US what’s probably the best spec to call up and how to I properly specify what I want on the drawing.

I found these different standards but couldn’t’ work out which was most appropriate or how to make sure I specified the oil supplementary coating.

ASTM D769, AMS2485, Mil-DTL-13924 & Mil-HNDBK-205

It looks like AMS 2485 is equivalent to the Mil DTL class 1 and is what I want but how do I specify that I want the oil post treatment?

Whatever I come up with I’ll have the engineer verify with the likely vendor but some of our vendors are a bit sloppy with specifying callouts and there’s a chance later production batches will go to a different vendor so I want to make sure the requirement is clear. Once again I can’t really justify getting the spec for this rare occurrence.

Thanks a lot.


KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[unclesyd]

I think you will find what you are looking for here. over the years I've used a lot of both Heatbath's and Park's products with excellant results.

http://www.heatbath.com/heatbath/products/black_oxide_finishing/black_oxide_for_ferrous_metals

 

[KENAT]

Thanks Uncle, I didn't see on there that it clarified which standard, it only showed the mil, or how to generically specify the supplementary coating.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[unclesyd]

I would give them a call as they have been quite helpful in the pass.

When we used oil we used a water resistant oil by LE or at times for long storage we used MolyKote Metal Protector. We used both a warm immersion tank and airless sprayer to apply the coatings dependent on the quantity.

Anecdotal:
I got my butt in trouble with the warm oil tank (150F) when the fire protection people found out about it and wanted me to put fire suppression system on the vat. I was able to get them to opt for a automatic closing cover. Just 15 minutes before there first visit our heat treater had just quenched as 65 pound part in our oil quench tank and fire went to the ceiling. I don't think they ever saw the quenching of part in oil the whole time we done our heat treating in house. As the tank only had a lift off cover.

 

[TVP]

KENAT,

Definitely do NOT use ASTM D 769 or MIl-HDBK-205. Either SAE AMS 2485 or MIL-DTL-13924 are sufficient. The MIL spec can be freely downloaded, so I suggest you use that one. Download it using the following link:

http://assist.daps.dla.mil/docimage...253ADC559B5F2&jsessionid=0630c60e37bb24124c7d

 

[KENAT]

Awesome TVP, I've been hesitant calling up Mil-Stds & the like lately because so many seem to be getting supplemented or replaced by industry specs, AMS etc. However seems it may be the way to go here.

So how does the below look for a not calling up hot oxide and oil for California:

FINISH: BLACK OXIDE COATING PER MIL-DTL-13924 CLASS 1 SUPPLEMENTARY TREATMENT PER MIL-PRF-16173 CLASS II GRADE 3. DIMENSIONS APPLY AFTER FINISHING.

I've told the engineer to check with our vendor/their supplier. Below is a link to the supplementary

http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=275356

Can anyone confirm it's ROHS (Reduction of Hazardous Substances especially lead & hexavalent chromium) compliant, I don't see why it wouldn't be but I've been wrong before.

Thanks unclesyd too.


KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[KENAT]

Guess I should have googled RoHS compliance before I posted, how does this amended note look.

FINISH: BLACK OXIDE COATING PER MIL-DTL-13924 CLASS 1 SUPPLEMENTARY TREATMENT PER MIL-PRF-16173 CLASS II GRADE 3. FINISHED ARTICLE TO BE ROHS COMPLIANT, NO HEXAVALENT CHROMIUM TO BE USED IN TREATMENT. DIMENSIONS APPLY AFTER FINISHING.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[TVP]

Looks good to me.