... diamond bits due to drilling equipment limitations.TSP core bits are set with Thermally Stable Polycrystalline cutters ... to be much reduced.Size Available of core bits"Q" series:AQ,BQ,NQ,HQ,PQ/AQTK, ... 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 ... 146, T6S 101,T6S 116T series: T36,T46,T56,T66,T76,T86Z series: Z46,Z56,Z66,Z76, ...