Question for you guys, both needed? Or just one? Both are roughly the same cost. The reason I ask is both can grind the flats on a knife, changing the grit can get the desired finish, and both will have variable speed. Any pros or cons you may have thought of for either of these pieces of equipment. I know the surface grinder can remove precision amounts of steel, and be angle adjusted to taper tangs for instance. But if you can put a distil taper on the pointy part of the knife, there no reason you can't taper a tang by hand also! Will the disc sander put a superior finish on the blade? Let me know your thoughts on these things, as you can tell I am on the fence again for which will take my dollar$! Cheers, Griff.