Our 1A1R diamond grinding wheel features man-made diamond, more consistent in shape than natural diamond, for sharp, even cutting action, durability and long life. Resin-bonded to produce a self-sharpening effect and even grit distribution. Can be used wet or dry on carbide, ceramic, glass, welds, quartz and other hard, brittle and short chipping materials. 150 grit / 100 concentration.  Measures 6" in diameter, has an arbor hole of 1-1/4" and the grinding surface measures 0.035"" while the diamond depth is 0.028".