I am a big fan of SKF. You can download models of all the drawings and they will give you the limit tolerances for the bores.
I would think you might overheat the components ofa ball bearing during the mold process. Especially if it is sealed.
You can check the temperature limits of bearings and compare to the molding temperature of the plastic:
http://www.skf.com/skf/productcatalogue/jsp/search/searchDesignationForm.jsp?newlink=first&action=cad&maincatalogue=1&lang=en
In Reply to Christopher Thompson:
I have an off topic question which consists of two main questions. I know
that bearings can be insert-molded (overmolded) into plastic, but has anyone
tried insert-molding a ball-bearing into plastic? If so, what
recommendations can you provide?
Secondly, if a bearing is press fit into plastic, is a secondary machining
operation required? I know ABEC tolerances should be used when press fitting
the bearing OD into a metal housing, but are those tolerances really
necessary if press fitting into a plastic housing? I would prefer to avoid a
secondary machining operation if possible.
As I do not know the whole scope of the project, I cannot provide any more
information. I would be interested in hearing about the experiences of
others who have tried this before.
Chris