... 3.ISO 9001:2008 4.Acid resisitance(%):>99.6% Hardness-9.5 Grinding Ceramic Ball, Inert White Alumina BallsProfessional manufacturer ... support media Al2O3:17%-99.5%Size: 3,6,9,13,19,25,38,50MMVODA Inert Ceramic Ball for ... Temp. max.>1100>1100148017601800 Mohs Hardness (scale)>6.5>7>7>7>7.5Crush StrengthKN/particle1/4 inch (6mm)>0.5>0. ... 8.92>5.33>5.28>82 inch (50mm)>9.7>9.8>6.22>8>15 Sample one:Sample two: ...