×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Zinc Plating Spec?

Zinc Plating Spec?

Zinc Plating Spec?

(OP)
Hi,

I would like to use a low or mild carbon steel for a part I am designing.  The part is a cylinder.  A low force (~2lbf) ball spring glides across the surface of the cylinder.  I also need to prevent it from rusting.  So, I would like to put a zinc coating on for corrosion resistance as well as strengthening the surface of the cylinder so the ball spring doesn't eventually wear grooves into it.  On my print, how should I call out the zinc plating?  Is there a standard that is typically used?  What thickness is appropriate?

Thanks!

RE: Zinc Plating Spec?

(OP)
I've done some more digging and it looks like a chrome plating will give me both a hard/wear resistant surface as well as excellent corrosion resistance.  However, I see that an undercoat of copper or nickel is standard.  Anyone know how thick the copper or nickel layer should be?  This is for bonding strength, I assume?  Is there a spec for the undercoat?

I'm also looking at using Al with a hard anodize, instead.  Considering the load is only ~2lbf, any reason why the hard anodize might not work?

Would one be preferable over the other in terms of cost or effectiveness (effectiveness at wear resistance and corrosion, that is)?

RE: Zinc Plating Spec?

At that load, a hard anodized Al surface should work fine. ASTM B 580 is the industry standard for such coatings, and I recommend specifying Type A (Engineering Hard Coat) with a thickness of ~ 25-30 micrometers.  If you want to specify hard chromium (also called engineering or industrial chromium plating), then the standard is ASTM B 650.  I recommend specifying a thickness of 10 micrometers minimum.  Hard chromium plating does not require a copper strike, that is only used for decorative chromium layers.

RE: Zinc Plating Spec?

I would suggest a surface treatment using QPQ. It would be cheaper than ENP or Hard Chrome. Using QPQ would protect the whole part instead of just the ID.

Petrotrim Services

RE: Zinc Plating Spec?

whats QPQ?

RE: Zinc Plating Spec?

I am in the Oil industry, we make equipment that is installed in an oil well. On our alloy steel parts, we call out the following:

Zinc plate, clear chromate @ thickness of .0002-.0004.

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources