... ,76,86,101,116,131,146 WCasing Tube (X and W Series)We are leading manufacturer of Impregnated/ surface-set diamond ... .X series casing (Casing Type: NX : O.D.88.9mm HX: O.D.114.30mmPX: O.D.139.70mm SX: O ... minimized. This can be important when drilling to greater depths.W series casing (Casing Type: BW : O.D.73.0mm NW ... Casing tube(BW,NW,HW,PW,SW,UW,ZW) & (NX,HX,PX,SX)