... , 28, 30, 32, 34, 36, 38 to 60(mm)Chisel drill bits are mainly used in mining,coaling,metaling, etc. We are ... air holes, carbide button shape and the face shape.chisel bits, button bits, cross bits, rock drill bitsModelTaper DegreeDiameterLengthSocket diaFlushing ammmmmmsideDY20-4154°2065152DY22-4154 ...