Cangzhou Great Drill Bits Co., Ltd | PDC bits | diamond bits | drill bits PDC bits ,diamond bits ,drill bits, core bits,coring bits,impregnated core bit, naturaldiamond core bit , pdc core bit ,impregnated diamond bit ,TSP diamond bit Cangzhou Great Drill Bits Co., Ltd. (Great) specializes in the R and D, manufacture, distribution and service of oil drilling tools and equipment. The leading products are high-performance diamond drill bits and engineering drill bits.