our dominant drill bits are chisel bits, cross bits, buttons bits ... guarantee the high quality and reliability of the products.Tapered Drill BitType --Chisel Bits / Cross Bits / Button Bits ... Diameter---28mm,30mm 32mm,34mm,36mm,40mm,42mm,44mmThread Drill Bits---Diameter: 51mm to 127mmThread Type---R22,R25, ... Rod---R25,R28,R32,R38,T38,T45,T51. Integral Drill Rod---H19/H22, Diameter---20mm - 42mm. rock ...