I respect all laws and personal designs, even unpatented, however. i didn't see any patent info on their site and I don't think you can patent a knife blade shape that has been in existence for years before he made it, it would be like trying to patent the shape of a tee shirt. But either way if you don't resell it no problem. Zulu is right using an unknown steel could be a waste of time for you. there are some checks you can do on steels by watching the sparks, using a hardness tester, or try drilling it. Just keep in mind if you over heat it you will lose the original hardness then you will have to guess at the temps needed to get the proper temper back. I have made a round knife from a saw blade years ago as well i use 1095 high carbon for all my blades great steel and easy to work with. Good luck and don't forget to show us the outcome.