As a guess 60 will cause you a problem.
There is no hard and fast rule on the number of tables that you can use but
there is a limit.
For instance:
You can only have a maximum of 255 fields in a query and a UNION query follows
that rule - so five fields times 60 is 300 fields which means you cannot do this.
Other rules that apply ??? Trial and error on my part or your part to discover.
You might be better off constructing a temp table and using append queries to
add all the records from all the tables into it.
John Spencer
Access MVP 2002-2005, 2007-2008
The Hilltop Institute
University of Maryland Baltimore County