brown aluminium oxide grit No. 14 to 220 # Aluminum oxide is a tough, hard material (Mohs hardness 9) with high strength, excellent wear and ... , grinding and hundreds of other applications. Sizes: 8#, 10#, 12#,14#,16#,20#,22#,24#,30#,36#,40#,46#, 54#, 60 ...