... manufacturer 2.BW,NW,HW,PW,SW,UW,ZW 3.NX,HW,PX,SX, 4. 46,56,66,76,86,101,116 ... ,131,146 WCasing Tube (X and W Series)We are leading ... -up against, providing twice the contact area of coupled casing and helping to prevent the threads climbing under heavy torque loads ... in geotechnical applications. DCDMA Casing tube(BW,NW,HW,PW,SW,UW,ZW) & (NX,HX,PX,SX)