How are brake drums made ?

Hello good folks.

I have a question, how are brake drums made. Some places I see that the drums are cast. And, I have seen cast drums. But, on my 1965 Dart i am a bit puzzled. It goes for some ther cars too.
It looks to me like the outer part is cast, while the disc on the drum is of a pressed steel plate, and then welded to the cast part. But, that is sort of a little hard to accept, would they really weld a regular steel plate to a cast iron outer ring ?
Or is the drum forged ? I mean the entire thing.

The reason for asking is that the disc on the drum where the 5 wheel bolt holes are is very thin, I would assume too thin to successfully cast it. And it also feels like a little flexible, and that is not a typical "cast iron" thing to be.

I am just curious.

Bill