... # 240# 320# 400# 500# 1000# 4000# 6000#Alundum carbide sharpening stone, oil stoneIngredients: corundum, carbide silicon, china clay, feldspar and dextrin ... branded abbrasive tools are produced in our factory. More Grindering stone/ oil stone / sharpening stone, please view our relative catagory Corundum grinding ...