Our casing tubes are all manufactured by CNC machines, ... and specializing in the design and manufacture of premium diamond drilling tools for the world engineering: geotechnical exploration, Mining ... surface-set core bit, PDC bits (core or noncoring), casing shoes, reaming shells, overshot, hoisting plug, water swiel, ... rod: BQ, NQ , HQ, PHD, BT, NT, HT casing tube: BW, NW, HW, HWT2.Core barrel: BQ,NQ, ...