... drill bit ISO9001 diamond drill bit bit good feedback NQ,HQ,BQ diamond drill bit /diamond core bitSize Available: "Q" ... series: AQ, BQ, NQ, HQ, PQ/AQTK, BQTK, BQ3, NQ2, NQ3, NQTT, HQ3, HQTT, ... , T6S 116 T series: T36, T46, T56, T66, T76, T86 Z series: Z46, Z56, Z66, Z76, Z86, Z101, Z116, Z131, ... can be made as your points or drawings. NQ HQ Diamond Drill Bit