Home /
Search 🔍
the Site

World's #1 finishing resource since 1989
No login needed: Chime right in

topic 59051

Anodizing Al precision miniature screws for electronic device

November 15, 2012

Q. Hi,

I am doing technology development job in company supplying precision fasteners/parts to electronic industry, e.g. cell phones and tablets.

There was inquiry from customer that they wanted some screws/inserts that are very light. We tried out both Al and Ti. Because Ti has much higher strength and hardness so customer finally opted for Ti.However, machining Ti has a very high cost.

I am thinking if the Al screws/inserts are subjected to anodizing followed by sealing, it might be able to replace Ti in such kind of application.

My question:
1. is it possible to do anodizing in batch process, without racking of the screws?
2. is the anodized layer very brittle? after assembly the screw, will the anodized layer remain intact?

I am very new in this area, please kindly give your comment. Thanks

Can Pi
fastening surface technology - Singapore

December 5, 2012

A. You might want to try 'basket' or 'barrel' anodizing. I assume that the part being mostly threaded, and with larger head than the stem, will result to minimum contact marks. There is no guarantee for 100% success. You will have to check each part using conductivity test. Why not use Al high strength alloy and temper, coated with Alodine or Iridite instead?

Dado Macapagal
- Ont., Canada

December 7, 2012

A. The anodic film formed on a sharp edge, like a thread, becomes 100% aluminum oxide, is very brittle, and breaks off.

robert probert

Robert H Probert
Robert H Probert Technical Services
supporting advertiser
Garner, North Carolina

December 11, 2012

thumbs up signThanks for your replies.
If the anodized layer is very brittle, it is then not able to withstand the impact during automatic assembly.

Can Pi
- Singapore

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

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

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2021 finishing.com, Pine Beach, New Jersey, USA