Yet another question by a newbie:

I have an extruded circle (a cylinder) penetrated by an extruded circular cut (a blind hole).  I have a second part that is a shaft made also by extruding a circle and extruding a circular cut down the middle.  I can align the shaft to go into the blind hole, but I can not make the shaft seat at the bottom of the hole.

How do I do that??

I don't really see (or know the right word for) a mate where the two faces touch.