Generally speaking, if I use mild steel parts, I get them Zinc Plated with a chromate film. On motorcars, most of the parts used under the bonnet are mild steel and do not rust. I don't believe they are zinc plated. What finish do they use?
Mark Z Mechanical Engineer - Cape Town, WP, South Africa ^
Some of the parts are aluminum, some are painted (probably galvanneal), and some are zinc or zinc-alloy plated with chromate or trivalent chromate films. And, looking under my hood, a lot of them have rusted after 5 years :-)
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