I bought repro Grill star and a set of bumpers.
All of the parts are chromed.
...the round barrel appears to be stainless but is also chrome plated.
...After getting a lecture from my local chrome plater on what he calls ”triple chrome plating” , I can not tell you if the same process was applied.
Last first: "triple chrome plating" can mean any number of things depending on who is telling you, but generally it is accepted to mean a three step plating process. First a copper plate, or "strike" as they say, then a nickel strike, followed by the chrome. Some platers may use a four step process, where there are two layers of nickel, a dull strike and a bright strike. It all depends on the plater and their work style.
The entire purpose of using stainless steel in automotive trim is to avoid having to further plate or finish the metal. There's a lot of stainless steel trim on various cars, OEM, over the years, that was just basically left alone.
I will not dispute that which I have not seen, so indeed you may have chrome plated stainless steel parts of some kind or another. But even Mercedes themselves, for example, used to make the wheel covers out of pressed steel, and then had it chrome plated when the parts were OEM for production. As the wheel covers went to just replacement part usage, they were then made of highly polished stainless steel.
Typically we know of stainless steel (from buying fasteners, maybe tools and what have you) in two common grades: 18-8 (often called type 304 but not exactly), or 18-10 (similarly, type 316.) That's 18% chromium and the 8 or 10 is nickel. Many of you will note that 316 anything is more costly than 304; but 316 is generally more corrosion resistant.
If somebody is reproducing parts, one might think they would be somewhat intelligent about it...but you never know. If you are going to use stainless steel, those common ones are probably not the proper alloy to use. Automotive trim done properly uses other grades, maybe one of the 400 series known to take a high polish. Do it out of the proper alloy and you won't need to chrome plate the part. But maybe they just use whatever they can get their hands on.
Back to wheel covers, OEM and aftermarket as a first class example. Somebody, before they were shut down, made a run of wheel covers out of stainless steel. They probably used 304, but who knows: they surely did NOT use an alloy that could take a high polish. When MB specified a new production run of the wheel covers, they sure as heck DID specify an alloy that could polish properly. I (along with many others) have these late generation OEM SS wheel covers. It's hard to tell them from a well preserved chrome plated example. But the reproduction ones? Perhaps they are "good enough"; certainly the price was. You be the judge...(OEM on left, reproduction on right)
Would STILL love to see that reproduction grill star and barrel from the Vietnamese manufacturer if anybody ever bought one...
