it actually looks like it came off some sort of heavy machinery ,simply
put just a bolt ,I used to work in a factory ad have seen studs ,smaller
but looked the same ,what I was told by the maintenance guys they are
used where high pressure is present the big end is where you would put
into the hole of the anchor point and the small one is where the plate
or whatever the piece that goes over it and the nut goes over the smal
end ,if you ever seen a stud when it pulls out ,it never pulls thru the
nut but the lowr mounting point ,thats the reason for it being bigger
gives more surface area to hold unto .
Probably what happened was someone was working on something had it out
to check tolerances on something left it on the bandsaw or set it down
"for just a second" and came back for it and someone else had or they
had knocked it off and probably landed in the machine instead of looking
for it they just got another ,and if you ever been in a bsy maintenance
shop ,they never would've heard it drop ,happens all the time ,but least
you got a nice little conversation piece and messing with people by
making up a humorous or unbelieveable story
have fun with your new trophy