I don't think it's a cultivator tooth. Don't believe they'd go thru all the manufacturing effort to drill all those holes, whats the point. I think you're missing alot of what it was. Bet if you traced it out on a paper and rotated it to get what the original shape was, it'll be round. If that's the case, more likely a pipe flange or the like. If you do that, post up the OD, ID and roughly the bolt hole ID's.