... drilling. They possess high penetration than conventional diamond core bit from soft to medium-hard formations, particularly ... 96, 113, 123, 133 and 153mm outer diameters. PDC core bit : BQ, NQ, NQ3, HQ, HQ3, PQ, ... hydrapower station grouting project ( wireline core drilling and double-tube core drilling)1.Drill rod:BQ,NQ, ... ,BQ,NQ,HQ,PQ, T2, T6 etc. Diamond core bit, reaming shell & shoe bit (syn. and ...