I've gotten a few plow edges in as a freebie to see if I can make knives with it. I can sharpen it straight out of the field sharp enough to shave arm hair. I've already ground a blade. (I know blackmsithing grinding a knife is sacrilige, I just didn't wanna run the risk of trying to forge something that thin into something thinner). I'm 95% sure they're either John Deere or Case brand. What should I quench and temper them at? OR just cut one into sample peices and oil quench one, water quench one, and let one normalize. Then temper all ar 500 for an hour and see what happens.

Yes

They may be cast iron but if steel, they are probably C1080 or something similar. Spark test first then perform the tests you mentioned.

Hayden, A.G.Russell once flattened, folded and honed an aluminum beer can till he could shave with it---doesn't really tell you much about it's bladeworthiness.

OTOH cultivating items are generally fairly high C to deal with abrasion issues. I'd try an oil quench and then try to break it.

Alright... And I'm gonna try the beer can thing... With a Dr. Pepper can of course

Dont forget that bronze was used for many years before steel was even dreamed of, as I showed an apprentice once, I can get a nice edge on balsa wood. it wont last either, but you did not mention how you tested your blades edge holdling ability.

I tried it against the 2 by 4 that my little bench vise is attatched to, it stayed decently. The peice kinda looked like a mini-hatcher head. I couldn't resist making it look "hatchet-ish". It held up decently, now just to find a few wider peices to toy with