Hi, I've recently been grinding a lot of toolbits after a long hiatus from mach ining. One thing that crops up in my mind - why do some wheels heat the par t so much more than others? The obvious answer is the sharpness of the cutt ing media. When I sand brass on a fresh belt, there is much less heat than with an old belt because presumably the heat goes away with the chips, and there is more cutting and less rubbing. I have various wheels for shaping a nd sharpening, from stone to various hardness of abrasive impregnated rubbe r. It seems the harder the wheel, the more heat. Finer grits heat more, but that seems a smaller issue. Is the answer simply that the surface of the s ofter wheels wear away faster and continually expose fresh abrasive?
9 years ago