finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
(current
topics)
topic 4715

Problems with Tube Nuts


(2000)

We have a problem with some tube nuts. The nuts are low carbon steel. The old system was to zinc plate the nut, add a yellow (yes, hexavalent) chromate, then coat the nut with an organic aluminum-rich paint. The nut is then put on a plated low carbon steel tube and then tube is endformed.

We have two problems right now. The paint gunks up the threading on the nut so that it can not be screwed in. Also, the nut has problems passing corrosion testing requirements (cyclic testing). We are thinking of going to just zinc nickel with yellow or bronze chromate or making the nut out of brass or stainless steel.

My thought on using another material is that we will create galvanic corrosion from dissimilar metals and even though we solve our nut problem, the tube will start seeing problems. I don't know if zinc nickel would be good or not.

Let me know what you guys think. I am looking for some educated comments, but nothing too in-depth. This is just free chat. I am also looking for general solutions, not a sales pitch for a particular product. Thanks!

tim neveau
Tim Neveau
Rochester Hills, Michigan


(2000)

I think that a mid phos EN would work very well for the application.

If SS were cheaper, I would do some testing. nickel zinc would come close to your plate and paint scheme price and do it cheaper.

James Watts
- Navarre, Florida



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView CURRENT TOPICS

Disclaimer: It's not possible to 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 may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.