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