... difference size drill bit with international standard Core Bits are widely used in mineral exploration industry and geological survey. diamond core bits which are ... Available: Q series: AQ, BQ, NQ, HQ, PQ,BQ3, NQ2, NQ3, HQ3, PQ3...T2 series: T2-46, T2-56, T2-66, T2 ... , HMLC, LTK48, LTK60,EWK, AWK. AW,NQ,PQ,HQ,PQ,NQ3.HQ3 diamond drill bits