Grills

I was interested in using an old hamburger maker on which to cook burgers, but I wanted to know what kind of metal was under the black teflon coating? When you placed your hamburger patty onto the grill circle, there was a drainage piece that allowed burger fat juices. Were the grilling plates, themselves, made of alluminum, steel, iron or what? LMK and thanks.

It would seem they would be similar to skillets that have a Teflon coating, aluminum or stainless steel……