Use on metals?? castings?? rivets?? rust</br>Use for sharpening?? deburring and general purpose grinding</br>1/8"nk</br>Do not run in excess of 30??000 RPM</br></br>Product Description</br></br>Dremel Mfg. Division Aluminum Oxide Grinding Stone?? DRE945</br><br/>http://www.amazon.com/gp/product/B00004UDIVV_04