Sorry for beating a dead horse, There has already been plenty written concerning the grinding of tungsten but a while back one post caught my eye. I wish I rememebered who it was from. The post had a link to a grinding wheel on E-bay under "Lapidary Materials" My problem has been finding a 180-220 grit wheel that would fit a 1/2 inch arbor on a six inch grinder. I found it in that section. I bought from a seller named "rocklady1" ,,good price,(about $55 after shipping) and I have not had a finer arc yet. If you are having trouble with a wandering arc I gaurantee this will help. They even sell adapters if you have an odd sized shaft on your grinder. This may be common knowledge for all I know but I am very impressed with my results,,Adam