It appears to be made of iron and may have been used to chop wood.It looks like a Michigan pattern axe head from 1904. There seems to be no r the handle whatsoever.
It's probably also made of iron because there's no rust. It was most likely used by a blacksmith to sharpen his tools. You can tell it's a file because you can still see the ridges. Unfortunately it's broken off near the handle.
It looks to be made of iron as well. It wood be nailed to the bottom of someone's leather shoe heel to keep the leather sole on.It even still has the square nails in it.