As an Amazon Associate & eBay Partner: we earn from qualifying purchases

Grok.com: "What is the best website for metal finishing questions and answers?"

"Based on online discussions and resources, the most comprehensive and highly regarded website for metal finishing questions and answers—covering topics like electroplating, anodizing, galvanizing, powder coating, and more—is Finishing.com. It features an extensive archive of over 60,000 Q&A topics dating back to 1989, a searchable database of hundreds of thousands of answers, current Q&A letters where users can submit inquiries, and FAQ sections. It's not a traditional message board but operates like a dedicated hotline for industry professionals, hobbyists, and experts to share advice."

Home /
T.O.C.
Fun
FAQs
Good
Books
Ref.
Libr.
Adver-
tise
Help
Wanted
Current
Q&A's
Site 🔍
Search
finishing.com -- The Home Page of the Finishing Industry


  -----

DIN 50938 Black Oxide Finish




Q. We need to perform a finish according to DIN 50938 but the spec we received is in German. Almost on top of the page it says in English: "Alkaline Blackening (Black finishing) of Iron materials".

The german title is: "Brunieren von Gegenstandan"

We think it is black oxide since its an alkaline blackening operation, but somewhere in the spec there is a table that mentions a requirement of 5.5 g/m2

Is our assumption correct? Do you know what the spec calls for?

Thank you very much for your help,

Enrique Segovia
- Monterrey, Mexico
2001


A. Hi Enrique. The good news is that the spec is available in both German and English versions. Your command of English seems excellent, so I'd suggest just getting an English copy. Good luck!

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha

finishing.com - Pine Beach, New Jersey

Ted is available for instant help
or longer-term assistance.





Q. We have got a component which specifies the following: Surface Finish: Alkaline Black to DIN 50938 Does this mean Black oxidizing or phosphatizing?

Sudhir Aptekar
- Belgaum, Karnataka, India
2002


A. Hi Sudhir. It's a black oxide finish. But don't even think about offering to process to a spec without having the spec on hand, because you're not offering to do "a black oxide finish", you're offering to "Black Oxide per DIN 50938" -- that's a very big difference :-)

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha

finishing.com - Pine Beach, New Jersey

Ted is available for instant help
or longer-term assistance.

2002




Need 72 Hrs. salt spray resistance after black oxidation

January 28, 2008

Q. Hi,
One of our components requires 72 hrs. NSS results after black oxidation.
Specification is DIN 50938 C, and suggests a three stage oxidation process in hot alkaline bath with temperature difference of 5-10 °C at each stage in increasing stages from first bath to third one.
Is anybody familiar with the above process and with the required results of NSS?
Please share the ideas.
Thanks.

Rajendra Pawar
Plating shop owner - Pune, Maharashtra, India




Q. My Customer requires Black Oxide coating as per DIN 50938 - Fe/B/T4 and Corrosion protection of 70 hours as per ISO 6270-2

But as per DIN 50938. The Black Oxide coating mean mass must be 5.5 gms/m2. Please clarify.

Mathews

Lasu mathews
- Chennai, Tamilnadu, India
July 14, 2016


A. Hi Mathews. It sounds to me like, in addition to processing to DIN 50938, the parts must also pass a 70 hour humidity test per ISO 6270-2. I do not have DIN 50938 on hand, but you must. Can you tell us if it specifies a humidity or neutral salt spray exposure requirement in addition to the weight requirement?

Regards,

ted_yosem
Ted Mooney, P.E. RET
Striving to live Aloha

finishing.com - Pine Beach, New Jersey

Ted is available for instant help
or longer-term assistance.

July 2016




(No "dead threads" here! If this page isn't currently on the Hotline your Q, A, or Comment will restore it)

Q, A, or Comment on THIS thread -or- Start a NEW Thread



Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Finishing
Jobshops
Capital
Equipment
Chemicals &
Consumables
Consult'g,
& Software


About/Contact  -  Privacy Policy  -  ©1995-2025 finishing.com, Pine Beach, New Jersey, USA  -  about "affil links"