our dominant drill bits are chisel bits, cross bits, buttons bits, DTH bits We are a professional company which is ... as well, and our dominant products are chisel bits, cross bits, buttons bits, DTH bits with high, medium and low air pressure, ... --Chisel Bits / Cross Bits / Button Bits Diameter---28mm,30mm 32mm,34mm,36mm,40mm,42mm,44mmThread Drill Bits---Diameter: 51mm to 127mmThread Type---R22,R25 ...