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Plating or Anodizing of Aluminum Gears

Q. Hello,
I'm currently making Al 7075 pinion gears and I wanted to protect them from corrosion and improve their hardness with anodizing. Since in this particular application the decorative appearance and color is also an issue I was wondering could anybody tell me if decorative anodizing is enough or is hard anodizing a necessity when it comes to gears. The gear won't be in use too frequently (it lifts a working bench a couple of times a day) and and maybe if I heat treat the Alu 7075 to make it harder, the decorative type 2 anodizing would be hard enough?
The concern is would the type 2 anodizing wear off during prolonged use..

Thank you very much

David Mares
- Novi Sad/Serbia
September 16, 2021

⇩ Related postings, oldest first ⇩

Q. I am trying to figure out what the best plating for my appication. I have these two reworked 80 pitched gears that I am using to steer a mirror in the laser. These surfaces will be rubbing agianst each other as you turn them to adjust the lens so I need a plating that will meet mil spec, has good wear, color really is not an issue but would like it to be clear, gold or black, thickness has to be around .001. Can someone please suggest a plating to use.

Thank you,

Kenneth Stebbins
- Bedford, Massachusetts

? You say that you need a material that will meet the MilSpec. If you know the MILSPEC then you know what the required plating is.

Gene Packman
process supplier - Great Neck, New York

A. Other than color, electroless nickel is the superior candidate. If the gear can not stand the bake cycle to harden the nickel, you can get a very hard coating with minimal bake by using a low P EN bath.

James Watts
- Navarre, Florida

A. I think this is a prime candidate for hard coat anodizing. The anodized coating can be .001-.002" and will be a very dark brown in color. It will wear extremely well. If you enhance the anodizing with a fluoropolymer spray you'll have a fantastic coating. Try that out.

Daryl Spindler
Daryl Spindler, CEF
decorative nickel-chrome plating - Greenbrier, Tennessee

Remember that .002 thick of hardcoat will increase your thickness by appox. .001

Chris Snyder
plater - Charlotte, North Carolina


A clarification to the last two responses.

Only 1/2 of anodize thickness is build-up. .001" of thickness will build-up .0005" per surface.

Tim Hamlett
Tim Hamlett, CEF
- West Palm Beach, Florida, USA

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