... symmetric drilling tools, eccentric drilling tools, standardized API system casings, bit shanks and casing tubes which are fit for hydraulic drilling ... ,T45,T51Face Shape---Plate, Concave, Convex.Bit Shank & Coupling sleeve---R22,R25,R28,R32,R38,T38,T45,T51Down-The-Hole Tools1 ... 6.0M.Thread Rod---R25,R28,R32,R38,T38,T45,T51. Integral Drill Rod---H19/H22, Diameter---20mm - 42mm. T51 Thread button bits