I bought a house that has hot water baseboard heating (house dates to mid 60s). I'm taking the covers off to vacuum the fins. I found a couple of metal clips on the floor. I'd like to understand what they are for and where they go. They're about an inch wide, "squarish" u-shaped. Most baseboards don't have these, but I did manage to find one that does. They're clipped on the underside of the fins near a metal bracket that holds the cover on.
I know there are expansion cradles, but these seem to be made of plastic and they easily slide on top of the lower part of the bracket that holds the cover on. The clips I found are metal and they really don't fit inside the bracket (a VERY tight fit).