I have a Lisle grinder http://www1.shopping.com/xPO-Lisle-91000-LISLE-DRILL-GRINDER-U-S-A#keyFeaturesArea I don't see them for sale anywhere any more. Maybe Lisle quit making them. I have had guys working for me that can sharpen a bit on a grinder. If I try it, I get it off centered and wind up with holes too big.