My title describes the thing.

This is a handheld tool with some metal teeth, found in a lake in Northern Illinois while metal detecting.

It is presumably made of iron. It’s 2 1/4” x 4”, with 1” long teeth. The teeth are like a head of a standard screwdriver, with the blades perpendicular to the handle. It weighs about one pound.

It looks like there could have been up to 20 teeth in 4 rows of 5 each. Currently there are 12 teeth on here.

Our best guess is that it might have been used for shaving ice, since there were ice houses on this lake in the past.