... may provide various types of Rock Drill Bit.I .Taper connection rock drill head.1.> Chisel Type Bits ( ... diameter is form 38 to 102mm)2.>T-screw drill ,screw connecting sleeve. (T38,T45,T51 The diameyer ... from 66 to 140mm)2.Down the hole rock drill with high air pressure. (The diameter from 90 ... to 178mm) Down the hole drill bit can available INGERSOLL .RAND DHD,ATALAS COPCO ,KAISHAN ...