... Tube 1.We are manufacturer 2.BW,NW,HW,PW,SW,UW,ZW 3.NX,HW,PX,SX, 4. 46,56 ... to prevent the threads climbing under heavy torque loads. This is by far the most popular type of casing used in ... geotechnical applications. DCDMA Casing tube(BW,NW,HW,PW,SW,UW,ZW) & (NX,HX,PX,SX)