-- The Home Page of the Finishing Industry

on this site
current topics
The world's most popular metal finishing site, and striving to be the internet's friendliest corner

topic 35590

Hard Anodize on 6061-T6 Alum


I am designing a small spring retainer. I am thinking about using 25 mm X 25 mm X 50 mm 6061-T6 Aluminum block and hard anodise it because the retainer must slide over a Teflon rail.
As the spring opens and closes inside this block, the block moves a bit with the spring - which is what we like to see.
What does hard anodize do to a mechanical integrity of this aluminum block? Does it make the block stronger, or stiffer?

Mike Kojima
- Irvine, CA. USA


Tougher - no way! Stiffer - lose again! Hardcoat, or any anodic coating, is strictly a surface enhancement. While thicker, hardcoat is still aluminum oxide - a brittle, ceramic like SKIN that makes the surface more abrasion resistant, but in metallurgical sense, actually weakens the material - lowering the fatigue strength (this is why thin Type I chromic anodize is preferred over thicker Type II sulfuric anodize). Basically, the thicker the oxide, the more degradation to the materials fatigue strength there is. If strength is what you need, consider an alloy change - 7075 alloys are stronger than 6061 alloy is stronger than etc. Beauty is skin deep but doesn't give one a clue as to how strong one is!

milt stevenson jr.
Milt Stevenson, Jr.
Anoplate Corporation
supporting advertiser 
Syracuse, New York

Anoplate banner

Q, A, or Comment on THIS thread SEARCH for Threads about ... My Topic Not Found: Start NEW Thread

help wanted ad
    PPI Aerospace, Warren MI:
Process Control Manager (9/13/19)

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

©1995-2019, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.