... Various Models Of PDC drill Bit 1)Certified by ISO9001&API2)Covers all IADC codes3)Size:4 3/5" (116.8mm)~17 ... ,diamondBrand Kingdream,CS,JZBit Diameters 4.1/2", 4.3/4", 5.1/8", 5.5/8",,5 7 ... 5/16"(8mm),1/2"(13mm),5/8"(16mm),3/4"(19mm),etcBlades 2~9 WingsModel Number GD1905,GD1904 ... is balanced which resulting better stability of the bit.3) Multiple types of high performance PDC cutters are strategically ...