... on drilling equipments as well, and our dominant products are chisel bits, cross bits, buttons bits, DTH bits with high, medium ... guarantee the high quality and reliability of the products.Tapered Drill BitType --Chisel Bits / Cross Bits / Button Bits Diameter---28mm,30mm 32mm ... .0M.Thread Rod---R25,R28,R32,R38,T38,T45,T51. Integral Drill Rod---H19/H22, Diameter---20mm - 42mm. tapered ...