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Info needed: Chrome Plating and Anodizing

1999

I am having a small quantity (3,000) of zinc die cast parts produced. They are of an oval shaped piece that is 1 1/4 x 1 7/8 x 5/16 thick. They need to be Chrome plated, as this unit is part of a handle, and will be subject to wear from use by the hands. Because of this wear factor, I would prefer the finish to be of Hard Chrome. I need to find a source to do this for me. The diecast company has suggested a zinc alloy of ASTM AG40A. Would this alloy be a good choice or is there a better choice for plating? Strength is not a factor, but appearance is.

I also need to match the finish on an anodized part. Is there anywhere I can have this tested to tell me what the process is so I can find an anodizer to anodize this for me. Would anyone have any ideas or suggestions to help with any of this? Thanks.

Paul Kubinski
- Reno, NV

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Actually, you don't want hard chrome. Please see our chrome FAQ.

Matching the color and texture of an anodized part should not really require lab testing. In all likelihood it's a sulfuric acid anodized part with an organic dye, and any anodizing shop will be able to make a reasonable approximation with a bit of trial-and-error work.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
1999

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I agree with Ted that Hard Chrome is not required for a decorative part like that. A good Nickel/Chrome would do, preceded by a good Copper Strike/Plate. I'm not familiar with that ASTM spec. for the Zinc. Most of the parts we plate are Zamak 3 or 7. I'm not sure of the percentages of other elements the type you stated but it's usually easy enough to modify the preplate cycle to accommodate it.

Jim Conner
Anoplex Software

Mabank, Texas USA

1999

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1999

Hi Paul , I agree with the others , you don't need hard chrome , you need a decorative finish , & preferably one that matches a good automotive specification . I would recommend that you look to have applied a good copper strike , followed by a "Duplex" Nickel coating , of not less than 1.5 thou thick with 1.0 thou being in "semi-bright" nickel the rest being in bright nickel and this then followed by chromium plating ( microcracked ) of a minimum of 20 millionths of an inch thickness .

This coating will withstand all the handling you require .

Of course to obtain an any way decent finish on Zinc diecast parts you will need to have them polished first , and that is the real tricky part finding a half way decent polisher who understands polishing diecast . For more help in both selecting the right plater & polisher I suggest that you call Solin Products Inc, Anaheim California. Henry is a supplier of plating technology in your area and has been in the business for many years , his knowledge of who does what , & where is encyclopedic , use my name as a point of introduction and I am sure you will get favorable service.

best regards

John Tenison - Woods
- Victoria Australia