It is white and harder and more brittle than A.It features strong cutting force.steady chemical property excellent insulation .Its knoop’s hardness is 2200-2300kg/mm2. It can be used for making bonded and coated abrasive tools.wet or dry blasting It is suitable for grinding of the hard and strong bending strength materials.Such as chilled steel,alloy steel,high -speed and high carbon treel and suitable for crystal,cutting emiconductor and high carbon steeland suitable for crytal,cutting semiconductor and monocrystalline and polycrstalline.Meanwhile ,it can be used as insulation,special ceramics and super refractory materials,etc.