... drilling in project. AQ,BQ,BQ3,NQ,HQPQ,PQ3Double tube electroplated diamond core bit and reaming shellΦ46,Φ56,Φ59,Φ66,Φ75 ... higher abrasiveness strata. AQ,BQ,BQ3,NQ,HQPQ,PQ3Wire-line electroplated diamond core bit reaming shellΦ56,Φ59,Φ75,Φ91,Φ95 AQ ... ,BQ,BQ3,NQ,HQPQ,PQ3 NQ/HQ Impregnated diamond core bit/Electroplated Diamond Core Drill Bit/Surface set diamond core bits