This is a diamond·CBN wheel using phenol and ather resin bonds. Two properties, longer life and high sharpness of the wheel, which usually contradict each other , coexist. Fully utilizing the characteristic of its low elastic coefficient, this wheel is mainly used for grinding work placing greatest importance on highquality finishing surfaces.Basically,this is a matrix type that is suitable for grinding work that produces small chips. Recently, porous type wheels are being developed.