I was contemplating switching to stainless steel for all my metal chain, earring hooks and other components. I thought it would wear better than the so-called "silver-plated" iron or brass chain which I usually use. The silver coating eventually either wears off or dulls drastically over time, with exposure to the environment, and becomes very ugly. In the picture below, the earring on the right is one I made three years ago and never put away. The one on the left is new. I don't think the hooks can even be polished, since they're not true silver.
But I discovered that although stainless steel is supposed to be "stainless", first it just is more resistant to corrosion, not impervious; and second, there are different grades of stainless steel, the most common one being 304 stainless steel, which contains chromium (the substance which makes it withstand corrosion) and nickel -- usually 8% nickel, but can go up to as much as 35%.
This isn't good. Some people are allergic to nickel.
WebMD and the Mayo Clinic both say surgical grade stainless steel (and not just any type, but 316L stainless steel in particular) should be safe for those with nickel allergy to wear. That means I have to carefully read the labels when purchasing materials... and if I switch to stainless steel, I have to keep some of the previous thingies on hand just in case I need to switch them out for a buyer. It makes things complicated. I don't like complicated!