It will depend on your skill as Ken said. How thick of a piece are you starting with. The problem, as I see it, trying to go to 1/8 all by hammer is that as you approach your desired thickness you are one hanmer mark away from a problem you cannot fix. If you want 1/8 and you forge to 1/8 you have no room to smooth out hammer marks. If you want forge finish steel then maybe it will be OK. If you want machine or hand finish maybe forge thicker then grind to finished dimensions. Just my opinion...Ken and I don't leave hammer marks so its been a while Lol Lol.