I just put a new floor down and before that I remove the toilet flange when I when to but the new flange on the flange will not fit on. The house is about 50 yrs old.

I have to assume the pipes and flange is cast iron. Right? Please explain, in detail, what your problem is. Did you remove the lead and oakum joint? What material is the new flange. Details! We need details to answer questions. Thank you, Tom

How is a toilet flange attached to the drain or floor?