We have our own file names for fasteners and each time we bring in a new one, we use favorites to "rename" them.  Looking in the ANSI Metric bolts and screw section, for SHCS there is "socket head cap screw_1am.sldprt" and "socket head cap screw_am.sldprt".  Why are there 2 and what is the difference?  This leads to another oddity I was seeing.  When going into older files, before we "renamed" the fasteners, I do an "edit toolbox dimension" and rename them.  The list of what fasteners have already been renamed will vary in the same assembly model.  Is this because at one point I inserted the ..._1am shcs and another size came in as ..._am?  I hope my rambling makes sense.

Rob