Granite Surface plate Density:2970-3070kg/m3 Compressive strength:245-254N/mm2 Flexible grinding amount: 1.27-1..47N/mm2 Granite Surface plate major mineral composition for pyroxene, plagioclase, a few olivine, black mica and trace magnetite, black color, the precise structure, after one hundred million years of aging, quality of a material is even, good stability, strength, high hardness, can in ...