assorted old iron insulator posts and utility pole hardware

First pic is my current collection of such in their plastic milk crate, 2nd is with everything all laid out.

These are all old hardware parts used mostly to fasten glass/ceramic insulators to wooden utility poles, with a few other random bolts and bits that'd otherwise have been used for something else up there in the air.

I don't think I realized (before getting this bunch) that insulator posts actually existed in so many (3 or 4 here, at least) 'thread sizes'. The six in pic 3 are too big to accept standard/typical old glass and ceramic insulators, a couple more at the bottom of pic 4 are too small -- only the 3 in the lower RH corner are that seemingly 'exact' size.

Besides insulator posts, the only really interesting thing is the long 'eyebolt' near the middle of pic 4, which would have been thru-bolted on a post to probably hold a guy-wire or other tensioning cable helping keep everything upright. Note that most all of these parts that have machine threads/nuts also have large heavy gauge square washers on them, evidence of the 'extra heavy duty' task they were designed and expected to do. Another interesting detail I've noticed but can't yet explain (if the pics show it or not) is that those big square nuts in most cases aren't typical of such, with their inner 'flat sides' having a curvature cut into it as if it was intended to hold onto something round, which the big square flatwashers certainly *aren't* and, at least to my common logic also sorta defies the whole principle of how any kind of machine nut is otherwise able to be turned/tightened to whatever it fastens...??