Any ideas what kind of steel? Any suggestions on what to do with them?

Being a gear, they’re generally heat treated so it probably has carbon in it. They’re usually 1045 or 4140 from what I dealt with in machine shops but some are also mild steel depending on what it was used for.

Optical emission spectroscopy if your a scientific smith: heat it up cool it rapidly and check hardness and brittleness with a new file and a hammer if you’re a tribal smith..Gears make an interesting visual component for metal sculptures, ornamental iron gates, and funky garden animal construction.

With those round (ish) cut teeth there's a good chance it's meant to be beat on a bit, meaning a bit softer steel. Best bet is to spark test to get a basic idea or try quenching a piece and file/snap test it. Some gears also have either different materials for the middle bit and the teeth themselves, or a differential heat treat, so keep that in mind and maybe normalize before quenching for any tests. Another option is to clean it up and throw it in the etch if you wanna see if there's any differences throughout the piece

I think that is cast steal

I don't know about anyone else but I think it's hard saying, this is like taking a picture of a yellow pencil and asking what wood it's made from if you had a spectrometer that could help though

Idk but when you get an answer let me know! 🍻

So you are cogged up then?

Whatever you do with the rest I would keep a section with a few teeth that can be clamped in a vice or wield a bit on to make a hardy tool.

You never know when you might need to bend something to some weird shape and having a few weird shapes things sitting around as a swage can be really useful.

Case hardened mild steel.

Powdered metal gear.

Sunflowers for the yard.