Just about any ole belt sander will do the job. I found one at a pawn shop for $50-- been sharpen my zwickeys on it for years- works great, its fast, and I don't even bother to touch em up w,a file, after the belt. Edges are rough,( belt is rough 50) but very sharp. I suspect that if you looked closely at them w, a magnifying glass-- you see something that approximated a fine -serrated edge- which is a nice why to get more cutting edge- been taking deer w them for 15yrs. no probs. they cut better than the ones I use to spend hours honing w/ files and stones. I now spend about 30 sec.s sharpening one. Just get lay it on the belt,at the angle of the bevel,(good lightening is most helpful) develop a burr, flip it over and just touch it down to remove some of the burr-- Your good to go.