Is there a way to do a concentric mate that is "close".  Because of decimal round off error or mm to inch conversion sometimes a distance between mating parts will be, say, 1.0625 on one part and, say, 1.063 on the other, and the two holes will not concentrically mate.  Is there a tolerance function that I don't know about?  The real world is seldom exact and I can't believe this is not a common problem.  There should be some type of "tolerance" check box that would allow a mate as long as it is within a certain distance.  This would be similar to slot mate, but in two directions.  If this is not available, this would be a good suggestion for future upgrades that, at least, the concentric mate would have a tolerance field.