... china, and specializing in the design and manufacture of premium diamond drilling tools for the world engineering: geotechnical exploration, Mining ... core barrel (AQ-PQ) and assemblies, synthetic diamond core bits, natural diamond surface-set core bit, PDC bits (core or noncoring), casing ... HQ,PQ, T2, T6 etc. Diamond core bit, reaming shell & shoe bit (syn. and surface-set, PDC)4.Drill tool: hoisting ...