What kind of disc are you using? I find the disc that gives a better grind is the thin metal cutting disk, I use a disc that is 0.8mm Thick. Get one of those on your angle grinder and try again. The Angle plays a big part aswell if your going in at an angle like this: / (45`) will give a lighter and not very sharp grind. If you can go in at an angle like this ¦ (90`) it will give a much deeper and sharper grind. Heres the discs i use : http://www.screwfix.com/prods/71334/Abrasi...-22mm-Pack-of-5 And heres a tutorial on grinding : http://thrashed.blip.tv/file/280326/