... of black gloss, precise construction,even character, nice stability, high strength and hardness, but also no rust, acid&alkali-proof, ... , the granite can still retain even character, stable, high strength and hardness, and can keep high precision at heave duty ... production and measuring works at laboratory.Proportion,2970-3070kg/m3Compression strength,245-254kg/mm2Flexible grinding capacity,1.27-1.47N/ ...