A. rock drilling bits B. taper chisel bit C. quality is closed to Atals Copco drill ... 28, 30, 32, 34, 36, 38 to 60(mm)Chisel drill bits are mainly used in mining,coaling,metaling, etc. We are ... bit diameter, number of air holes, carbide button shape and the face shape.chisel bits, button bits, cross bits, rock drill bitsModelTaper DegreeDiameterLengthSocket diaFlushing ammmmmmsideDY20-4154°2065152DY22 ...