PDC Coal Mine bit 1.features of large torque, wide drilling range and ... 3.e-6 segment good quality 4. wooden case PDC Coal Mine bitIt is mainly connected with spiral drill shank and works ... with coal electric drill machine or portable drill machine. Due to the ... Design Service Offered Ø28, Ø30, Ø32,Ø76,Ø89, etc.. PDC Coal Mine bit