Old gear teeth are on cogs about an inch and a half across, not idea what machinery they spent their useful life in.
100mm macro lens, and focus stacking to get all the detail.
To me it looks like ancient architecture, maybe lying buried in a jungle while rust consumes it.
Hi Jim, I love the character of rusted iron and this certainly displays that well.
The composition works well, helped by the focus stacking. Thanks for sharing.