Permissions are NOT inherited to files contained within directories. You can still have a world readable directory, with every file within being root-owned and inaccessible to other users, and that's not unusual (look through your /etc dirs).
You're looking for something explained like this maybe: https://superuser.com/questions/264383/how-to-set-file-permissions-so-that-new-files-inherit-same-permissions#264406
The gist is that there is no default way of achieving what you want, but you should be able to achieve something you want one way or another.
If you get more specific about your use-case, there is probably a solution.