I found this solid brass disk yesterday at a civil war skirmish site. It looks suspicious but I can't i.d. it.
I'm posting top, bottom and side views. Any ideas? Thanks!
VHS07 is correct... it is an internal component from a (2oth-Century) water supply line gate-valve. I don't know the proper name for that component, perhaps "shutoff disc", but you can see it in the image below.
Giving credit... that image was originally posted here in What-Is-It? by our fellow ID-helper Taz42O.