... of natural or synthetic diamond utilizing a hard matrix compound on the face of the bit. The diamond set design ensures sufficient ... to be much reduced.Size Available of core bits"Q" series:AQ,BQ,NQ,HQ,PQ/AQTK,BQTK,BQ3,NQ2,NQ3 ... ,NQTT,HQ3,HQTT,PQ3,PQTTT2 series: T2 46,T2 56,T2 66,T2 76,T2 86 ... ,T2 101T6 series: T6 76,T6 86,T6 101,T6 116,T6 131 ...