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Coating for small steel parts in continuous outdoor environment

April 7, 2009

I am trying to specify the best bang for the buck coating for some small steel parts. The parts are small oval-shaped brackets formed from 14 Ga. mild steel sheet. They measure about 3/4" in width and about 5" x 3" oval. Right now the parts are stamped and then formed. There is also a lag bolt welded to the bottom of the part.

The parts will be used to anchor tubing covered in foam insulation to the roof and sides of houses. This means they will be outdoors indefinitely in various environments. What would be the most suitable coating for this application with cost in mind? My first reaction was galvanizing but we have also used e-coat, nickel coating, and zinc coating in the past for similar parts. I am open to any option though.

Thanks for the help!

Brian Coppola
Product Designer - Springfield, MA, USA

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Hi, Brian. If appearance is not important, I'd probably go with galvanizing. Remember that the threads must be specially cut because galvanizing is thick. If appearance is important I'd probably go with zinc electroplating followed by electrophoretic lacquer.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 9, 2009