... drilling tools, eccentric drilling tools, standardized API system casings, bit shanks and casing tubes which are fit for hydraulic drilling ... --Chisel Bits / Cross Bits / Button Bits Diameter---28mm,30mm 32mm,34mm,36mm,40mm,42mm,44mmThread Drill Bits---Diameter: 51mm to 127mmThread Type--- ... Rod---R25,R28,R32,R38,T38,T45,T51. Integral Drill Rod---H19/H22, Diameter---20mm - 42mm. tapered drill bit