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.