PDC bit----PDC inserts are set in a cast matrix head using round premium 13.4mm inserts. PDC bit are widely used in coalfields exploration and for open hole drilling. They possess high penetration than conventional diamond core bit from soft to medium-hard formations, particularly in soft, sticky formations such as coal, oil shale, tarsands, and shallow oil and gas.PDC bit : 56, 60, 76, 96, 113, 123, 133 and 153mm outer diameters. PDC core bit : BQ, NQ, NQ3, HQ, HQ3, PQ, PQ3, T2 76, T2 86, T6 101, T6 116, T2 131 and so on.