... and researching on drilling equipments as well, and our dominant products are chisel bits, cross bits, buttons bits, DTH bits with high, medium ... top production technology, such as electro-hydraulic forging hammer, seal chamber furnace lines, precision machine tools and ... of the products.Tapered Drill BitType --Chisel Bits / Cross Bits / Button Bits Diameter---28mm,30mm 32mm,34mm,36mm,40mm,42mm ...