... with high, medium and low air pressure, symmetric drilling tools, eccentric drilling tools, standardized API system casings, bit shanks and casing tubes ... projects and foundation constructions etc.Our company produces advanced drilling tools with the top-grade manufacturing equipments. The mission is ... Drill Rod---H19/H22, Length: 0.5M to 6.0M.Thread Rod---R25,R28,R32,R38,T38,T45,T51. Integral Drill ...