back of fan bend?

[adjunog]

There is a bend around the center. Is this normal? Should the back of the fan be flat? It had been rubbing against the aluminum part too.

[adjunog]

Sorry, I had answered my own post. Lol. I can still use more comments and I'll leave the post for reference. Thanks y'all.
Ok never mind I had compared to some fans. Mine seems to be more flat than others and knowing that it can be to closer to the fan shroud. However the others are more domed so it doesn't hit.