Contact US

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!

*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

hard/soft anodize. . .

hard/soft anodize. . .

hard/soft anodize. . .

what are the differences between the two??
maybe a thicker/thinner difference??
and i see class I class II etc..
any help--thank you

RE: hard/soft anodize. . .

There are two standard specifications for anodic oxide coatings on Al: MIL-A-8625F and ASTM B 580 - 79 (1995).  MIL-A-8625F is available for free from the following website: http://astimage.daps.dla.mil/quicksearch/

ASTM B 580 can be purchased through a number of entities:
ASTM at http://www.astm.org
ASM International at http://www.asminternational.org
Global Engineering Documents at http://global.ihs.com

The types or classes fall into two general categories: hardcoat anodizing and not hardcoat anodizing.  Typical anodizing baths use either chromic acid or sulfuric acid as a source of oxygen.  The coating thickness from these baths is usually ~ 1-10 micrometers in thickness.  These coatings can be subsequently sealed, or painted over, etc.

Hardcoat anodizing is typically performed in sulfuric acid baths, resulting in much thicker coatings: ~ 50 micrometers.  This produces much better resistance to wear and abrasion.  Upong sealing, these coatings also provide outstanding corrosion resistance.

There has been at least one other thread on eng-tips regarding anodizing, so use the SEARCH function and find it, as I posted some information there as well.  An excellent website with technical information on the various anodizing processes is http://www.metalast.com, which is the website for Metalast Inc., a commercial coating company in the U.S. that specializes in anodizing.  Another good source of information is Volume 5 of the ASM Handbook, titled Surface Engineering.  The section on Anodizing is about 11 pages.  A good university library should have this book, or you can visit the ASM website that I included earlier for more info.

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! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close