"as it were" and "so to speak"

According to the New Oxford American Dictionary they are close in meaning but not quite the same:...

as it were = in a way (used to be less precise), e.g. "... areas that have been, as it were, pushed aside."



so to speak (or say) = used to highlight the fact that one is describing something in an unusual or metaphorical way, e.g. "... del