... 2,ISO9001 ♦ The black silicon carbide is of high hardness, brittleness.♦ Chemical washed and water washed ... as cutting and making jewelry, jade, agate. ♦ Grinding of gray cast iron, white cast iron, bronze, brass, ... washed by acid, F12-320# Sic>90% standard of P:P80-2500#. SymbolScriesGrit SizeChemical Properties % Grit SizeSicF. ... 0.30 0.30 2.5 0.60 0.80 1.20 1-3 3-5 5-8 Silicon Carbide grit