... synthetic diamond are distributed in the depth of impregnated bit's matrix series. The matrix layer of the ZM contains a uniform ... of the formation to be drilled. Size Available: "Q" series: AQ, BQ, NQ, HQ, PQ/AQTK, BQTK, BQ3, NQ2, NQ3, NQTT, HQ3 ... with us if you need detailed specifications or catalog. NQ & HQ impregnated diamond core bit 6mm & 12mm Casing & Casing shoe bit ...