Kevin - the easy answer to your question is: I have no idea.
I have another around here somewhere but not sure where? It started about 1x4x1/2" tapered to the front(business) end of the tooth. It had two clips welded to it that held it to the drag scraper/grader. I found two on my road and hope I can find relocate the other around here because it made a nice knife. Definitely carbon and takes a HT but just good ole junkyard steel of unknown property. If the other turns up I will take a pic.
I did the lava lamp pattern with mustard.