... -Ran We are a professional company which is specialized in making and researching on drilling equipments as well, and our dominant ... , symmetric drilling tools, eccentric drilling tools, standardized API system casings, bit shanks and casing tubes which are fit for hydraulic drilling ... ,R28,R32,R38,T38,T45,T51Face Shape---Plate, Concave, Convex.Bit Shank & Coupling sleeve---R22,R25,R28,R32,R38,T38,T45 ...